Cheslea residents are fighting to landmark a townhouse that newly discovered evidence indicates may have been a stop on the Underground Railroad.

The W. 29th Street home was once owned by Abigail and James Gibbons, two prominent 19th Century abolitionists with ties to Harriet Tubman’s famed escape route for slaves.

Construction on a penthouse addition to the building has been ordered stopped by the city as the Landmarks Preservation Commission considers whether to declare the townhouse a landmark.