The 1920s saw economic prosperity in the United States driven by new technologies like the automobile, mass-produced by Henry Ford using assembly lines, and installment buying, which let consumers purchase expensive goods without full payment up front. However, this led many to take on more debt than they could handle. When the stock market crashed in 1929, wiping out stock values, businesses closed and Americans lost their jobs en masse, plunging the country into the Great Depression with unemployment reaching 33%.