Surface cars were rerouted into the Public Garden Portal when the Tremont Street subway opened in 1897.

By the 1930s, auto traffic through Copley Square and Boylston Street (which, unlike Huntington Avenue, lacked dedicated medians for trolleys) caused major delays to streetcars.

[1] The project was constructed by the Works Progress Administration during the Great Depression and allowed streetcars from Huntington Avenue to go underground through Copley Square, cutting 15 minutes off trip times.

[4] The station was closed on Sundays for some time beginning on February 1, 1981 due to budget cuts.

However, as a cost-cutting measure they were changed to be the only two underground stops on the Green Line where riders paid upon boarding the train, rather than when entering the station.