Between 1936 and 1950, National City Lines (NCL), a holding company sponsored and funded by General Motors, Firestone Tire, Standard Oil of California and Phillips Petroleum, bought out more than 100 electric surface-traction (streetcar) systems in 45 cities (including New York, Philadelphia, St. Louis, Salt Lake City, Tulsa, and Los Angeles). Those systems were ultimately dismantled and replaced with GM buses.
National City Lines was formed in 1936 as a holding company, for the express purpose of acquiring local transit systems throughout the country, mostly in medium-size cities. Many of those transit systems had already converted from streetcars to buses.
Additional factors enabled NCL to acquire streetcar systems in the first place. Because streetcars were the earliest heavy users of electricity, it was practical and economical for many streetcar systems to be owned by the electric utility companies themselves. As part of the New Deal, federal legislation was passed ordering the electric utility companies to sell off their businesses not actually providing electricity. Under the Public Utilities Holding Company Act of 1935, these streetcar systems suddenly became more readily available for takeover by NCL.
The formation of National City Lines had actually been preceded by other actions by GM. The company began investing in streetcar lines in the late 1920s the shortlived United Cities Motor Transit (UCMT), a direct subsidiary of GM which lasted from 1932 until 1935 when the American Transit Association (ATA) censured the company for converting streetcar systems to bus lines.
A company run by E. Roy Fitzgerald, a bus operator from northern Minnesota, was recruited to run NCL. Fitzgerald and his family had run a small bus operation in the small town of Eveleth carrying miners and schoolchildren. This small-town entrepreneurial image was sometimes used as a public relations tactic when communicating with journalists.
Controversy involves those transit systems which were still running streetcars when acquired by NCL, and whether they ultimately would have been converted to buses.
See General Motors streetcar conspiracy for a full discussion of the controversy.