After World War I, the American government adopted tariff and debt repayment policies to try to rebuild the economy. The tariffs raised prices on imported goods to benefit domestic industries. The government also forced allies like France and Britain to repay war debts, which created tensions. However, these policies did not prevent the onset of the Great Depression in 1929, which was largely caused by an unstable stock market and overproduction. Herbert Hoover was elected in 1928 due to optimism about the economy and his image as a self-made man, but many of the underlying economic issues remained.