Originally a streetcar line, it is now the Q59 bus route, operated by the New York City Transit Authority between Williamsburg and Rego Park, Queens.

It continues along Queens Boulevard until Eliot Avenue, where it turns left along the Long Island Expressway.

At Broadway, the Q59 makes another left and continues until it enters the Williamsburg Bridge Plaza Bus Terminal.

At various points in its history, the Grand Street Line has been served by horsecar, trolley, and bus, with service modifications implemented by New York City's mass-transit authorities in response to varying ridership levels (and associated revenues).

Initial construction of the line, by the Grand Street and Newtown Rail Road, began in September 1860.

[7] Its first section (from Williamsburg's Grand Street Ferry to Bushwick Avenue) was completed on October 15, 1860, with a public opening expected by the end of that month.

In 1949, the New York City Board of Transportation reacted to declining ridership by proposing the conversion of the line to a bus route.

The New York City Board of Estimate approved the change on October 13, 1949,[17] and the streetcars were permanently removed on December 11, 1949.

On June 25, 1979, seven westbound trips from Rego Park were added between 10:30 p.m. and 1:36 a.m.[20] On December 11, 1988, the line was relabeled to its current identifier, the Q59.

[23] Service was eventually extended to the Williamsburg Bridge Plaza Bus Terminal in 2010, and in September 2016, the eastern terminus of the route was relocated to 62nd Drive to avoid a hazardous U-turn at 63rd Road/63rd Drive, as well as provide a closer connection to Rego Center.

[37] On January 29, 2025, the current plan was approved by the MTA Board, and the Queens Bus Redesign will go into effect by Labor Day.