Seamen's Church Institute, 1925.

The Seamen's Church Institute was founded in 1834 by group of Episcopal men. Their original "building," constructed in 1844, was the Floating Church of Our Savior, a boat docked at Pike Street. This facility served to community of sailors that entered the city for some temporary amount of time from the seafaring life. The institute went through at least one other floating church and one other onshore structure before constructing their own 12-story building at 25 South Street in 1913. The building could house nearly 600 people and became a popular dormitory space for sailors and seamen.

In the wake of the Titanic disaster, survivor, socialite, and philanthropist Molly Brown insisted on a memorial for the victims. Installed at the top of the new Seamen's Church Institute building in 1913, the 60-foot-tall (including the large spire) lighthouse was a memorial for the victims. For decades a ball was lowered at noon as a commemoration and for ships anchored in the harbor to set their clock by.

In 1968 the Institute moved to a new building and 25 South Street was razed. The lighthouse was moved and reinstalled as part of the campus of the South Street Seaport Museum in 1976.