 The franchise given to the Sixth Avenue Railroad by the city in 1851 specified that it should extend its tracks "up the Sixth avenue to Harlem River, whenever required by the Common Council".Because Central Park was designated in 1853, the Sixth Avenue Line was only built to 59th Street.This long-dormant clause was used in 1894, when the Common Council ordered the company, then leased to the Metropolitan Street Railway, to build in what had become Lenox Avenue from 110th Street (the northern boundary of Central Park) to the Harlem River.