3 Jackson is a suspended[2] trolleybus line operated by the San Francisco Municipal Railway.

From the outbound terminal at Presidio Avenue and California Street, buses loop around the block via Walnut and Sacramento back to Presidio and run north to Jackson Street.

Outbound buses operate on Sutter from the inbound terminal at Sansome Street.

The Sutter Street Railway was originally a horsecar line, opened in 1866, which was converted to cable car operation in 1877.

[3][4] In 1902 the company was consolidated into United Railroads of San Francisco which later became the Market Street Railway.