United States: history 1918–45

New York celebrates news of the surrender of Japan in 1945. Following the dropping of the US atomic bombs on Hiroshima (6 August) and Nagasaki (9 August), and the invasion of Manchuria by the Russian army, the Japanese government accepted the Allied terms for unconditional surrender on 14 August. The instrument of surrender was signed on board the US battleship Missouri in Tokyo on 2 September 1945, signalling the end of World War II.

For the history of the American colonies before independence see America: colonial history to 1783. For the period leading to the Civil War see United States: history 1783–1861. For the Civil War and Reconstruction see United States: history 1861–77. For the era of Progressivism and World War I see United States: history 1877–1918.

The interwar period During the 1920s the USA enjoyed a period of unprecedented economic boom which, although not enjoyed by all its citizens, made the USA into the richest and most powerful country in the world. In 1929 the economic disaster of the Wall Street Crash led to the depression years of the 1930s. When Franklin D Roosevelt became US president (1933–45), he sought to tackle unemployment and poverty and rebuild US prosperity with his ‘New Deal’ economic and social policies. Roosevelt's policies were hugely successful, although by the end of the 1930s their impact was coming to an end.

US isolationism Following the end of World War I, the League of Nations was set up to solve international disputes through discussion rather than war. Although the League had been suggested by US president Woodrow Wilson, the USA refused to join it. The people and politicians of the USA wanted to avoid any contact with European powers that might lead the USA into another foreign war. In 1921 the Republican Party candidate, Warren G Harding, became president of the USA. Harding had been at the forefront of opposition to the USA joining the League of Nations, and his presidency, held until 1923, increased the neutral stance of the USA in foreign affairs.

The presidencies of Harding and Coolidge The most creditable achievement of Harding's administration was the calling of the international Washington Conference (1921) to prevent a naval arms race. Congress passed a bill limiting immigration into the country and starting the quota system. However, incidents such as the Teapot Dome Scandal, concerning the improper leasing of naval oil reserves, led to allegations of corruption in Harding's government. Harding died in 1923, before these allegations could be fully investigated.

After Harding's death in 1923 Vice-President Calvin Coolidge was sworn in as president. He won his own election in 1924. His policy was one of minimal interference with business, and the reduction of taxes, government spending, and national indebtedness. These things he accomplished. Another event of Coolidge's presidency was the signing of the Kellogg–Briand Pact (1928), an agreement between the USA and France to renounce war and settle disputes by peaceful means. The pact marked a different direction of foreign policy from the complete isolationism of the early 1920s. However, US involvement was to remain as a neutral player, and Coolidge did not commit the USA to any military involvement if the terms of the pact were not followed.

The 1920s were a period of general prosperity. This prosperity was built on the foundations of trade and financial speculation with shares and investments. However, the wealth was not spread among all Americans. Black Americans in the Southern states and white farmers remained as poor as they had been before the 1920s.

Although social change was occurring – by 1930 more than 50% of Americans lived in towns and cities – rapid social change produced many tensions. Prohibition (the outlawing of alcohol 1920–33), the revived Ku Klux Klan (a secret society aiming for white supremacy), and the Sacco–Vanzetti case (a miscarriage of justice caused by a judge's prejudice against the immigrant accused) were all products of the USA's post-war adjustment. Traditional religious attitudes remained strong in much of the USA, as was shown by the Scopes monkey trial (1925), when a schoolteacher was prosecuted in Dayton, Tennessee for teaching Charles Darwin's theory of evolution.

Prohibition By 1919 there was a very strong movement in the USA for the prohibition of alcohol production, sale, and consumption. The Anti-Saloon League and the Women's Christian Temperance Movement led the campaign, which proved so successful that by the elections of 1920 Congress contained twice as many ‘dry’ senators, who supported Prohibition, as ‘wet’ senators, who opposed it. In 1919, the Eighteenth Amendment to the US Constitution decreed that Prohibition would come into force from January 1920. Although successful in the first half of the 1920s, the law was increasingly ignored after 1925, and led to corruption and the spread of organized crime. Prohibition ended in 1933.

The start of the depression In 1928 Coolidge was succeeded as president by another Republican, Herbert C Hoover. In his foreign policy, Hoover was involved in the international naval disarmament negotiations leading to the Treaty of London (1930), an attempt to reduce armaments among the leading world powers. Once again, the USA aimed to be a neutral player, taking actions that would reduce the risk of involvement in another European war.

However, the most significant event of Hoover's presidency was the Wall Street Crash of October 1929, in which stock market prices collapsed. The outcome was general economic depression, which swept across the USA and then the rest of the world by 1930. Unemployment rose rapidly to more than 5 million, banks failed, and almost all sectors of the economy suffered hardship.

Hoover at first attempted to meet the crisis by a policy of ‘business as usual’. He failed to realize the significance of the depression, and did not take the dramatic measures required to stop the economic crisis affecting the USA. Hoover, like Coolidge and Harding before him, was a committed free market Republican. He did not accept that the government should interfere in the running of the economy, and wanted to leave the financial problems to sort themselves out as part of the natural economic cycle. In accordance with this thinking, he opposed direct government assistance to the unemployed. However the American people no longer supported free market attitudes, as they had done in the 1920s, and turned to the Democratic Party in elections held from 1930.

With unemployment approaching 12 million, in 1932 Congress accepted Hoover's proposal to set up a Reconstruction Finance Corporation to help industry through the economic slump. However, although the measure was useful, it was unable to halt the decline in Hoover's popularity.

The presidency of Roosevelt and the New Deal In 1932 Franklin D Roosevelt won the US presidential election in a Democratic landslide, with 472 electoral college votes to Hoover's 59 votes. In the House of Representatives, Democrats picked up 90 seats for a 310–117 majority; in the Senate, Democrats gained 13 seats for a majority of 60–35. The Democrats now had total control of the government of the USA.

Roosevelt took office as president on 4 March 1933. The first year of his administration was almost wholly taken up with measures to combat the depression and to bring into effect the New Deal that he had promised the nation. Prices were given an upward trend by ‘controlled inflation’, and the export of gold abroad was forbidden except under licence, thus taking the USA off the gold standard. Spending power was increased when employers pledged themselves under the National Industrial Recovery Act (June 1933) to agree to codes of fair competition, price and wage fixing, and other government measures. Agriculture was similarly helped by the Agricultural Adjustment Act (May 1933), which raised the prices of farm produce (commodities) and reduced overproduction, one of the causes of depression. The Farm Credit Administration was also set up in 1933 as part of the New Deal for agriculture.

The Congress elected in 1934 showed further Democratic gains. Its first consideration was the labour trouble that had arisen as a result of the National Recovery Administration. The latter was brought to an end the following year by a decision of the USA Supreme Court to the effect that it was unconstitutional. Shortly afterwards (1936) the Supreme Court ruled that the Agricultural Adjustment Act was also unconstitutional. Only the Farm Credit Administration remained. With the end of the Agricultural Adjustment Act production could no longer be controlled, and in 1936 Roosevelt resolved the problem with the Soil Conservation and Domestic Allotment Act. Government grants to farmers were made conditional on their making the best use of their land and preventing soil erosion.

Apart from the need to rebuild the US economy, Roosevelt was also faced with the massive problem of unemployment, with over 11 million out of work in 1934. Early responses to the problem included the setting up of such agencies as the Public Works Administration (PWA) and the Civilian Conservation Corps (CCC). In 1935, however, the Works Progress Administration (WPA) was created, with a budget of $5,000 million. The agencies set up to organize the New Deal became known as the ‘Alphabetical Agencies’ because of their initials. In providing employment for a wide variety of groups, including artists, the WPA symbolized the new idea of government responsibility that was the mark of Roosevelt's presidency. The Social Security Act (1935) was further evidence of this change in government attitude. In April 1933 the Tennessee Valley Authority was established to revitalize one of the most depressed regions in the country through government investment.

As a result of the setbacks that the New Deal had received at the hands of the Supreme Court, Roosevelt embarked on a ‘Second New Deal’, strengthened by his re-election to a second term in 1936. Roosevelt at once set about the reform of the Supreme Court, but the bill was rejected by Congress. The senior justice resigned, however, and was replaced by one more sympathetic to the New Deal. A Monopoly Investigation was authorized by Congress, and the antitrust laws were revived. A new Agricultural Adjustment Act was passed in 1938.

Problems with the New Deal In addition to the problems caused by the Supreme Court's action against the National Industrial Recovery Act and the Agricultural Adjustment Act, Roosevelt also faced opposition to his plans. Many business people and rich Americans resented having to pay higher taxes and being forced to give trade unions more control over their working practices. They were supported by the Republican Party opposition, who did not believe in the necessity for the large amount of government intervention in the economy demanded by the New Deal. Many state governors also resented Roosevelt's interference in their local affairs through his New Deal plans and agencies.

Although the New Deal did change the lives of many Americans, it was not the perfect solution to all the problems of the USA. In 1939 unemployment was still nearly 10 million, twice what it had been in 1931. It was not until the entry of the USA into World War II in 1941 that real falls in unemployment occurred, as vast amounts of war materials began to be produced and millions of men went off to fight in Europe or Asia.

The economic effects of the New Deal were not as successful as Roosevelt had hoped for either. Spending by US consumers on goods in shops was still only three-quarters of its 1929 level by 1938. The rise in the price of food and manufactured goods stimulated by Roosevelt's actions led to poorer Americans being unable to buy all that they needed to survive. In addition to this, the New Deal labour laws concerning pay did not protect the rights of women or black men. Their wages were legally allowed to be lower than white men. When the Agricultural Adjustment Act set about reorganizing farm production, its quota systems were unfairly applied to black farmers, and millions of them were forced to leave their farms, as they could not sell their produce.

US foreign policy in the 1930s The policy of the New Deal was conducted against a background of foreign affairs that were becoming increasingly disturbed. The World Economic Conference held in London in 1933 had broken down largely through the USA's preference for economic isolation. In spite of this, a Trade Agreements Act was passed in 1934, allowing the president to negotiate treaties for the mutual reduction of tariffs up to a maximum of 50%. With this mandate, Cordell Hull, the secretary of state, successfully concluded a number of treaties, particularly with Great Britain, Canada, and the countries of South America. The Latin-American treaties were a facet of the good-neighbour policy to which the president gave expression at an Inter-American Conference for Peace held in Buenos Aires in 1936.

The US attitude to the possibility of war in Europe was shown by the passing of three Neutrality Acts in 1935, 1936, and 1937. In April 1939 Roosevelt tried to remove the threat of war in Europe by a fruitless appeal to Hitler. Congress, however, rejected the president's proposal to amend the Neutrality Act, which was not in fact revised until November 1939. It then became permissible for the USA to sell arms to those nations able to pay for them in cash and to transport them in their own or other non-US ships. There was still a strong isolationist feeling, but Canada was already at war, and there was the prospect of Great Britain continuing the war from there if the UK were overrun. The USA and Canada entered upon joint measures of defence. Two years earlier Roosevelt had promised US aid if Canada was invaded, this being consistent with the Monroe Doctrine.

US aid to the Allies The common ground of both isolationists and interventionists was the need to rearm the USA and re-equip its forces. By the autumn of 1940 the USA was practically on a war footing. For the first time in US history military conscription was introduced in peacetime. Roosevelt showed that ‘preparedness’ transcended politics, and in June 1940 appointed two Republicans, H L Stimson and Frank Knox, to the posts of secretary of war and the navy respectively.

US sympathy was largely on the side of the Allies, and the Battle of Britain encouraged the USA to send all aid to Great Britain ‘short of war’. A valuable measure of aid (September 1940) was the transfer of 50 destroyers from the USA to the British navy in return for a 99-year lease of bases in Newfoundland, the Bahamas, Jamaica, and elsewhere in the West Indies.

Presidential elections were held in 1940. Both Republicans and Democrats supported Roosevelt's foreign policy and were united in the wish to hasten US preparedness. The election was therefore fought on domestic issues. Roosevelt, departing from tradition, was nominated for a third term. Roosevelt gained a larger majority than anticipated, polling 27,243,466 votes against the Republican Wendell Willkie's 22,304,755.

Roosevelt's entry upon a third term was marked by the Lend-Lease Act, which was presented to Congress on 6 January 1941 and became law on 11 March. In spite of anti-Soviet feeling, Lend-Lease credits were granted to the USSR after the German invasion on 22 June 1941. By that time Roosevelt had declared a ‘state of unlimited national emergency’ (27 May). US expeditionary forces were sent as a protective measure to Greenland, Iceland, Dutch Guiana (Suriname), and elsewhere. On 14 August the terms of the Atlantic Charter (outlining the war aims of the Allies) were announced, following a secret meeting between Roosevelt and British prime minister Winston Churchill on a battleship in mid-Atlantic.

US entry into World War II Meanwhile, Japan's adherence to the tripartite Axis pact with Germany and Italy was giving concern in Washington. The trade agreement with Japan had lapsed (26 January 1940), and had not been renewed. During 1941 relations became critical after the Japanese occupation of Thailand (August 1941). Diplomatic conversations were conducted in Washington between President Roosevelt and the Japanese ambassador.

Behind this diplomatic screen Japan prepared for war, and on 7 December 1941 struck from the air against the US naval base at Pearl Harbor, Hawaii, crippling the US Pacific Fleet and giving Japan naval supremacy. On 11 December Germany and Italy also declared war on the USA. Shortly afterwards Churchill went to Washington to confer with Roosevelt. For details of the course of the war see World War II.

Pearl Harbor was followed by attacks on the Philippines, Hong Kong, and the Malay Peninsula. The Philippines were occupied by the Japanese by the end of May 1942. The effect was to release a tremendous production drive in the USA, which restored the country to full employment. As the year progressed the USA achieved several naval successes, stemming the Japanese advance (see Coral Sea, Midway, Battle of, Guadalcanal, Battle of).

The government's aim was to create an armed force of 10 million men, but the drafting of recruits caused a shortage of labour in industry. In April 1943 the president announced an economic programme to stabilize the cost of living. In spite of war taxation, increased income tax, and the increase in the national debt, inflation became a problem.

In Europe the USA maintained diplomatic relations with the collaborationist Vichy government in France, but supported the occupation of the French colony of Madagascar by the British in May 1942. The US landings in French North Africa followed in November under the command of Gen Dwight D Eisenhower. The next stage in war diplomacy was the Casablanca Conference in January 1943, the first time in the history of the USA that the president was away from the country in wartime.

Domestic affairs in World War II The Congressional elections in 1942 had resulted in Republican gains, and this marked a growing opposition to the liberal tendencies of the Roosevelt administration. The Anti-Inflation Act of 1942 was swept away, and efforts to control spending and to tax war profits were rebuffed. The cost of living rose sharply, bringing protests and strikes from organized labour. Domestic conflicts, sharpened by the approach of the presidential elections in 1944, did not, however, seriously hamper the war effort.

In foreign affairs Roosevelt's prestige was high. After his return from the Tehran Conference, Roosevelt in his annual message to Congress (11 January 1944) called for a National Service Law, backed by laws to tax war profits, control the cost of food, and stabilize prices. Congress was not responsive. It was not until July, however, that Roosevelt announced that he would stand for a fourth term. By that time domestic policy receded before the events in Europe, following the Allied invasion of German-occupied France in June 1944.

It was against this background of war that the 1944 election was fought. Roosevelt was renominated, with Harry S Truman as the vice-presidential candidate in place of Henry Wallace. The Republican candidate was T E Dewey, governor of New York. In the elections in November Roosevelt's popular vote was 25,602,505 while Dewey's was 22,006,278. Foreign policy had been kept outside party politics, and, with the cooperation of Arthur Vandenburg, the Republican leader, foreign policy was now bipartisan.

International cooperation in World War II Following the Yalta Conference in February 1945 between Roosevelt, Churchill, and Stalin, invitations were issued by the USA, Great Britain, and the USSR to 51 nations to take part in a conference to be held at San Francisco to discuss the future of the world organization – the United Nations – sketched out earlier at the Dumbarton Oaks conversations of 1944.

The opening of the conference on 25 April 1945 was overshadowed by the death of Roosevelt. Vice-President Truman succeeded to the presidency. While the conference was in session, there came the news of the surrender of Germany. The collaboration of the USA with Great Britain, the USSR, and France in dividing Germany into occupation zones emphasized the need for amicable relations, particularly between the USA and the USSR. Truman dispatched Harry Hopkins to Moscow. This paved the way for the meeting of Truman, Churchill, and Stalin at the Potsdam Conference.

On 28 July 1945 the Senate ratified the United Nations Charter (drawn up at the San Francisco conference in June) by 90 votes to 2. It seemed that isolationism as a political force was ended. The Senate also ratified the Bretton Woods agreements (founding the World Bank and the International Monetary Fund), and decided that the USA should take part in the UN Food and Agriculture Organization.

In August 1945 the war in the Asia–Pacific theatre was ended by the dropping of atomic bombs on Hiroshima and Nagasaki, which brought about the Japanese surrender. The war was at an end, but the atomic bomb figured largely in the problems of peace; controversy over the control of it broke out at once. A Congressional Committee was set up and resulted in the MacMahon Bill, which became law on 1 August 1946, establishing control by means of a civilian Atomic Energy Commission.

For US history after 1945 see United States of America.