Steam locomotives were invented in the mid-1800's and ruled the rails for a century. Early locomotives were quite small, but evolution over the decades created behemoth articulated locomotives of the 1940's. By 1950, diesel locomotives of standard designs offered railroads substantial operating cost savings, and by 1959 the steam locomotive era was over.

Today, about 1200 steam locomotives are preserved in municipal parks, museums, and private collections. About 170 of those are considered "operational", but many of these are in need of major repairs which can easily cost a half million dollars or more.