Comment by canucker2016

from https://www.pbs.org/wgbh/americanexperience/features/1900-id...:

    In 1850, the US was home to 19 millionaires. But the years following the Civil War had seen a considerable increase in membership of that exclusive club. By the end of the 1890's the number of millionaires in the US had swelled to more than 4,000.