Map of trolley routes. From "Across New York by Trolley", by Frederick A. Kramer (Quadrant Press, 1975). See larger image.
By 1890 the twenty-four separate lines of the street railways in Manhattan were consolidated as the Metropolitan Street Railway with full transfer privileges between all lines. Electrification of the lines began, and fewer horses were seen on the streets of New York City. The electric trolley drew its power in Manhattan from electric rails in the streets. Trolley cars provided an alternate means of transportation to the college. At their peak, trolleys linked all boroughs except Staten Island, though they also ran there.
By 1885 the development of the four elevated lines in Manhattan and the northward expansion of the business and residential districts had decongested the streets sufficiently to allow the reintroduction of the horse-drawn passenger vehicles which did not use the tracks of the street railways. The Fifth Avenue Coach Lines began operating in Manhattan with horse drawn coaches; by 1908 all of its coaches were motor coaches.
New bus which replaced the Amsterdam Ave. Trolley. From "1948 Microcosm". Courtesy of the CCNY Archives. See larger image.
In the 1930s Mayor Fiorello LaGuardia set out to establish a coherent policy for "surface" transportation, which in his view, meant eliminating trolleys in favor of buses. He awarded franchises to many private bus lines and by 1936 the only trolleys left in Manhattan were those operated by the Third Avenue Railway Company. Their routes included City College.
The trolley replacement program was suspended during World War II, but by 1948 almost all trolley routes in Manhattan had been replaced by buses, and by 1957 they had disappeared from the other boroughs as well. In 1962 the Manhattan and Bronx Surface Operating Authority became a subsidiary of the New York City Transit Authority and in 1968 subways and buses came under the umbrella of the newly created Metropolitan Transportation Authority.