Working in oil on canvas, Gropper completed three mural projects: Two canvases for the Freeport, New York Post Office, 1938; Three canvases for the Stewart Lee Udall Department of the Interior building, Washington, DC, 1936-7 and installed in 1940; One canvas, painted for the Northwestern Brach post Office, Detroit, later moved and installed at Wayne State University Student Center, Detroit, Michigan.
