Dubuque's Historic Federal Building, formerly known as the U.S. Post Office and Courthouse, was completed in 1934. The building, which was designed in the art deco style, displays the strong rectilinear qualities that influenced modern architecture in the 1940s, 50s and 60s. The building's lobby vestibule contains two murals: ''Early Settlers of Dubuque'' (Bertram Adams, 1937) and ''Early Mississippi Steamboats'' (William E. L. Adams, 1937). The U.S. Post Office is still located on the first floor of the building.