 His two main principles were that the military should never interfere with the efficient running of the railroad and that rolling stock should be emptied and returned promptly to enable their re-use as transport.After his war service, Haupt returned to railroad, bridge, pipeline, and tunnel construction.He worked with the Richmond and Danville Railroad then was the general manager of Piedmont Air-Line Railway (from Richmond, Virginia, to Atlanta, Georgia), 1872 to 1876; Tide Water Pipe Line Company, 1875- ; general manager of the transcontinental Northern Pacific Railroad, 1881 to 1885; president of the Dakota and Great Southern Railroad, 1885 to 1886.