The 1920s economic boom
America’s Economic Starting Point
In 1910, the United States was already the world’s largest industrial economy. It had vast natural resources — coal, iron, oil and timber — spread across a continental territory larger than most European nations combined. A large and growing domestic market meant that American manufacturers could produce at scale. The country had already built a dense network of railroads that connected raw materials, factories and consumers.
These advantages gave the United States a head start when the First World War began in 1914. While European economies tore themselves apart, American businesses supplied both sides with weapons, food, chemicals and manufactured goods. By 1917, when the United States entered the war, American banks had lent billions of dollars to the Allied powers. When the war ended in 1918, Europe was physically devastated and financially exhausted; the United States was the world’s leading creditor nation.
By 1920 the United States produced approximately 40 per cent of the world’s manufactured goods. The First World War accelerated this dominance by destroying European industrial capacity while American factories profited from wartime orders. The United States also became Europe’s largest creditor, with massive loans to Britain and France.
Mass Production: Henry Ford and the Assembly Line
The most powerful engine of the 1920s boom was mass production. Henry Ford had introduced the moving assembly line at his Highland Park plant in 1913, revolutionising manufacturing. By breaking production into simple, repetitive tasks, Ford cut the time to assemble one Model T chassis from about twelve and a half hours to about 93 minutes by 1914. The cost of a Model T fell from $825 in 1908 to $260 by 1925, bringing car ownership within reach of ordinary workers.
The car industry did not just sell cars — it created demand for steel, rubber, glass, leather, oil and road construction. Economists estimate that by the late 1920s the automobile industry was driving around one in nine jobs in the United States. The spread of car ownership transformed American life: suburbs expanded, roadside businesses multiplied, and the country became more mobile and connected.
Electrification powered a consumer revolution. By 1929, around 70 per cent of American homes had electricity, compared with much lower rates in Europe. The growing power grid enabled mass production of electrical appliances — refrigerators, washing machines, vacuum cleaners and radios — that transformed domestic life. Companies like General Electric and Westinghouse expanded rapidly to meet demand.
The result was a self-reinforcing cycle: higher productivity in factories meant lower prices; lower prices meant more consumers could afford goods; more consumers meant higher output; higher output meant more factory workers with wages to spend. This virtuous circle defined the 1920s boom. Total consumer spending in the United States grew from approximately $48 billion in 1919 to nearly $79 billion by 1929.
Hire purchase (buying on credit) fuelled the consumer boom by allowing Americans to buy goods they could not afford outright. By the late 1920s, around 60 per cent of all cars and 80 per cent of all radios were bought on credit. This extended the boom but also left many households heavily in debt.
Republican Economics: Laissez-Faire and Protectionism
The Republican administrations of the 1920s — under Presidents Harding, Coolidge and Hoover — followed a philosophy of laissez-faire economics. The government cut income taxes for the wealthy, reduced business regulation, and refused to regulate the financial sector. The belief was that what was good for big business was good for America — often summarised in President Coolidge’s remark that “the chief business of the American people is business.”
Alongside laissez-faire, the Republicans pursued economic protectionism. The Fordney–McCumber Tariff of 1922 raised import duties to their highest level since the Civil War, protecting American manufacturers from cheaper European goods. In the short term, this benefited American industry; in the longer term, it damaged international trade and contributed to the fragility that made the Great Depression so severe.
The 1920s boom was real, but it was deeply unequal. Farmers did not share in the prosperity. During the First World War, agricultural prices had been high because of demand from Europe. When European farming recovered after 1918, American farm prices collapsed. Throughout the 1920s, millions of farmers — particularly in the South and Midwest — struggled with low prices, debt and foreclosures. By 1929, roughly half of all Americans still lived in rural areas, and most of them were not experiencing the “Roaring Twenties.”
Black Americans, recent immigrants and unskilled industrial workers also benefited little from the boom. Wages for unskilled workers rose more slowly than profits. The top 5 per cent of income earners received approximately one-third of all personal income in the United States in 1929. This concentration of wealth at the top and the over-reliance on credit created the conditions for the economic collapse that followed.