This large, handsome office building, demolished in 2014, was a telling symbol of the influence of the American Bridge Company in Ambridge, as befits the company that drew the plans for the Panama Canal's gates and the bridge over the Mackinac Straits. This rust-colored brick structure once oversaw the vast bridge works from its hillside terrace. The H-shaped building was highlighted by a full cornice, stone trim, and pediment-shaped gables over the central entrances on both sides, facing the river and the town. The grilles in the entry transoms featured the company's initials, and elaborate light fixtures flanked the doors. Windows, evenly spaced on each elevation, gave the drafting tables natural light. Keystones embellished the windows on the two lower stories, and stone lintels those on the third story.