The 1920s saw a period of widespread economic prosperity in the United States. New technologies and mass production techniques allowed goods to be produced more cheaply, enabling the middle class to purchase consumer items like cars, washing machines, and radios for the first time using installment plans where goods could be purchased on credit. This increased spending fueled a bull market on the stock exchange as more individuals invested, though many did so by buying on margin using loans, making them vulnerable. However, not all prospered as farmers struggled with overproduction and debt, and some workers faced layoffs as jobs were simplified by new assembly lines. This period of growth led to Herbert Hoover being elected president in 1928 on promises of continuing prosperity.