While electricity made life easier, nothing changed the American landscape more than the famous Model T Ford automobile, or "Tin Lizzy," which cost only about $440 by the middle of the decade.

The first primitive automobile was invented in the late 1890s, and the Model T had been in production since 1908, although only 18,600 of the cars were sold that year. Even by 1915, there were less than 2.5 million cars in a nation of 100 million people. By 1920, however, over 9 million Americans owned cars; by 1930, that number had skyrocketed to 26.5 million. In addition to Fords, Americans bought Chevrolets, Cadillacs, Oldsmobiles, Packards, Duesenbergs, Pierce-Arrows, and cars with such now-obscure names as Excelsior, Kissel, Locomobile, and Roamer.

In The Century, Peter Jennings and Todd Brewster assess the impact of these cars:

The burgeoning automobile age established a new sense of freedom and individuality: people no longer had to make their plans according...