As world trade slumped, demand for South African agricultural and mineral exports fell drastically. The Carnegie Commission on Poor Whites had concluded in 1931 that nearly ⅓ of Afrikaners lived as paupers. It is believed that the social discomfort caused by the depression was a contributing factor in the 1933 split between the "gesuiwerde" (purified) and "smelter" (fusionist) factions within the National Party and the National Party's subsequent fusion with the South African Party.

Having removed itself from the capitalist world system both by choice and as a result of efforts of the capitalist powers to isolate it, the Great Depression had little effect on the Soviet Union. A Soviet trade agency in New York advertised 6,000 positions and received more than 100,000 applications. Its apparent immunity to the Great Depression seemed to validate the theory of Marxism and contributed to Socialist and Communist agitation in affected nations. Many Western intellectuals, like New York Times reporter Walter Duranty, looked upon Soviet Union with sympathy, either ignorant of or ignoring reports about the Holodomor that killed millions of people.

The effects on the northern industrial areas of Britain were immediate and devastating, as demand for traditional industrial products collapsed. By the end of 1930 unemployment had more than doubled from 1 million to 2.5 million (20% of the insured workforce), and exports had fallen in value by 50%. In 1933, 30% of Glaswegians were unemployed due to the severe decline in heavy industry. In some towns and cities in the north east, unemployment reached as high as 70% as ship production fell 90%. The National Hunger March of September–October 1932 was the largest of a series of hunger marches in Britain in the 1920s and 1930s. About 200,000 unemployed men were sent to the work camps, which continued in operation until 1939.

In the less industrial Midlands and South of England, the effects were short-lived and the later 1930s were a prosperous time. Growth in modern manufacture of electrical goods and a boom in the motor car industry was helped by a growing southern population and an expanding middle class. Agriculture also saw a boom during this period.

President Herbert Hoover started numerous programs, all of which failed to reverse the downturn. In June 1930 Congress approved the Smoot-Hawley Tariff Act which raised tariffs on thousands of imported items. The intent of the Act was to encourage the purchase of American-made products by increasing the cost of imported goods, while raising revenue for the federal government and protecting farmers. However, other nations increased tariffs on American-made goods in retaliation, reducing international trade, and worsening the Depression. In 1931 Hoover urged the major banks in the country to form a consortium known as the National Credit Corporation (NCC). By 1932, unemployment had reached 23.6%, and it peaked in early 1933 at 25%, a drought persisted in the agricultural heartland, businesses and families defaulted on record numbers of loans, and more than 5,000 banks had failed. Hundreds of thousands of Americans found themselves homeless and they began congregating in the numerous Hoovervilles that had begun to appear across the country. In response, President Hoover and Congress approved the Federal Home Loan Bank Act, to spur new home construction, and reduce foreclosures. The final attempt of the Hoover Administration to stimulate the economy was the passage of the Emergency Relief and Construction Act (ERA) which included funds for public works programs such as dams and the creation of the Reconstruction Finance Corporation (RFC) in 1932. The RFC's initial goal was to provide government-secured loans to financial institutions, railroads and farmers. Quarter by quarter the economy went downhill, as prices, profits and employment fell, leading to the political realignment in 1932 that brought to power Franklin Delano Roosevelt.

Shortly after President Roosevelt was inaugurated in 1933, drought and erosion combined to cause the Dust Bowl, shifting hundreds of thousands of displaced persons off their farms in the Midwest. From his inauguration onward, Roosevelt argued that restructuring of the economy would be needed to prevent another depression or avoid prolonging the current one. New Deal programs sought to stimulate demand and provide work and relief for the impoverished through increased government spending and the institution of financial reforms. The Securities Act of 1933 comprehensively regulated the securities industry. This was followed by the Securities Exchange Act of 1934 which created the Securities and Exchange Commission. Though amended, key provisions of both Acts are still in force. Federal insurance of bank deposits was provided by the FDIC, and the Glass-Steagall Act. The institution of the National Recovery Administration (NRA) remains a controversial act to this day. The NRA made a number of sweeping changes to the American economy until it was deemed unconstitutional by the Supreme Court of the United States in 1935.

Early changes by the Roosevelt administration included:

These reforms, together with several other relief and recovery measures, are called the First New Deal. Economic stimulus was attempted through a new alphabet soup of agencies set up in 1933 and 1934 and previously extant agencies such as the Reconstruction Finance Corporation. By 1935, the "Second New Deal" added Social Security (which did not start making large payouts until much later), a jobs program for the unemployed (the Works Progress Administration, WPA) and, through the National Labor Relations Board, a strong stimulus to the growth of labor unions. In 1929, federal expenditures constituted only 3% of the GDP. The national debt as a proportion of GNP rose under Hoover from 20% to 40%. Roosevelt kept it at 40% until the war began, when it soared to 128%.

By 1936, the main economic indicators had regained the levels of the late 1920s, except for unemployment, which remained high at 11%, although this was considerably lower than the 25% unemployment rate seen in 1933. In the spring of 1937, American industrial production exceeded that of 1929 and remained level until June 1937. In June 1937, the Roosevelt administration cut spending and increased taxation in an attempt to balance the federal budget. The American economy then took a sharp downturn, lasting for 13 months through most of 1938. Industrial production fell almost 30 per cent within a few months and production of durable goods fell even faster. Unemployment jumped from 14.3% in 1937 to 19.0% in 1938, rising from 5 million to more than 12 million in early 1938. Manufacturing output fell by 37% from the 1937 peak and was back to 1934 levels. Producers reduced their expenditures on durable goods, and inventories declined, but personal income was only 15% lower than it had been at the peak in 1937. As unemployment rose, consumers' expenditures declined, leading to further cutbacks in production. By May 1938 retail sales began to increase, employment improved, and industrial production turned up after June 1938. After the recovery from the Recession of 1937–1938, conservatives were able to form a bipartisan conservative coalition to stop further expansion of the New Deal and, when unemployment dropped to 2%, they abolished WPA, CCC and the PWA relief programs. Social Security, however, remained in place.