Construction of the Custom House was authorized by U.S. President Andrew Jackson. It was completed in 1849. The tower was added in 1915 and made it Boston's first skyscraper. The structure sits on reclaimed land. Before land reclamatiom was done in the middle of the 19th century Boston's waterfront extended right to this building. The tower is 496 ft (151m) tall and is currently Boston's 17th tallest building.
The photograph was taken on October 30 a couple of days before Daylight Savings ended. As indicated on the clock (which is 22ft across) the time was 5:20 pm. The tower was in the shadow of a tall building but the setting sun light up Logan Airport which is in the background.