Yerkes was born into a Quaker family in the Northern Liberties, a district adjacent to Philadelphia, on June 25, 1837. His mother died of puerperal fever when he was five years old and shortly thereafter his father was expelled from the Society of Friends for marrying a non-Quaker.
After finishing a two-year course at Philadelphia's Central High School, Yerkes began his business career at the age of 17 as a clerk in a local grain brokerage.
He was a clerk in a grain-commission bouse, an exchange broker and a banker. When he failed in 1871 he refused to give any preference to the city of Philadelphia for bonds sold on its account, and was convicted of " misappropriating city funds, " and sentenced to two years and nine months in the penitentiary. After serving seven months of this sentence he was pardoned, and the City Council afterward passed an ordinance cancelling the municipality's claim against him. He established a banking business in Chicago in 1881; in 1886 got control of the Chicago City Railway Company; and within the next twelve years organized a virtual monopoly of the surface and elevated railway service of Chicago. He disposed of his street railway interests in Chicago, and removed lo London (1900). There he acquired in 1901 a controlling interest in the Metropolitan District railway, and by organizing the finances of the Underground Electric Railways Company he took an important initiative in extending the system oi London electric railways. Yerkes gave to the university of Chicago the great telescope installed in the Yerkes Observatory at Lake Geneva, Wisconsin, and gathered in his New York residence a remarkable collection of paintings, tapestries and rugs, which were sold at auction in April 1910 for $2, 034, 450. He died in New York on the 29th of December 1905.
He divorced with his first wife of over twenty-two years. Later that year, he wedded the 24-year-old Mary Adelaide Moore and moved to Chicago.
