A. Hoen & Co.
A. Williams & Co.
Abbot, Henry L.
Adams Express Company.
Alabama and Tennessee River Railroad.
Alabama. Railroad Commissioners.
Albemarle and Pantego Railroad.
Alexander, W. D. (William De Witt), 1833-1913.
Allegheny Railroad and Coal Company.
Allen, J. W.
Allen, Lane & Scott.
Allen, William A., C. E.
Alt, W. W.
Alter, R. H.
American Bank Note Company.
American Central Railway.
Anderson, J. A.
Anderson, P., civil engr.
Andrews, Israel De Wolf.
Annin & Smith.
Arkansas Central Railroad.
Arms, F. C.
Arrowsmith, John, 1790-1873.
Asher & Adams.
Atchison, Topeka, and Santa Fe Railroad Company.
Atchison, Topeka, and Santa Fe Railway Company.
Atlanta and West Point Rail Road Company.
Atlantic and Great Western Railway Company.
Atlantic and Pacific Railroad Company.
Atlantic, Mississippi & Ohio Railroad Company.
August Gast & Co.
Baltimore and Ohio Railroad Company.
Baltimore and Susquehanna Railroad Company.
Barney, Joshua, 1799 or 1800-1867.
Bayley, G. W. R.
Beckwith, E. G. (Edward Griffin), 1818-1881.
Bellaire, Zanesville and Cincinnati Railway.
Bellefontaine and Indiana Railroad Company.
Betts, J. Brognard.
Bien, Julius, 1826-1909.
Black Diamond System.
Blackford, W. W. (William Willis), 1831-1905.
Blanchard, Rufus, 1821-1904.
Boone, Albert E.
Boston (Mass.). Engineering Department.
Boston and Lowell Railroad Corporation.
Boston and Maine Railroad.
Boston, Hoosac Tunnel, and Western Railway.
Bouvé, Elisha W.
Bouvé, Ephraim W., 1817-1897.
Bowen, John T., approximately 1801-1856?
Braxton, Carter M.
Bridgman, E. C.
Brooklyn City Railroad.
Brown, H. C.
Browne, D. Jasper.
Burgin, John F.
Burlington and Missouri River Railroad Company.
Burlington, Cedar Rapids, and Minnesota Railroad Company.
Burr, David H., 1803-1875.
Burr, Henry A.
C. D. Andrews & Co.
Cady, A. M.
Cairo and Fulton Railroad Company.
California and Nevada Railroad.
Campbell, Henry R.
Cappeller, W. S. (William S.)
Carleton, Guy H.
Carter, T. J., active 1844-1873.
Catawissa, Williamsport and Erie Railroad Company.
Central Ohio Railroad Company.
Central Railroad Extension Company of Long Island.
Charleston and Savannah Railroad.
Chesapeake and Ohio Railroad Company.
Chesbrough, Ellis Sylvester, 1813-1886.
Chester, Iron Mountain, and Western Railroad.
Chicago & Northwestern Railway. Land Department.
Chicago & Pacific Railroad.
Chicago Great Western Railway Company (1892-1909)
Chicago and Canada Southern Railway Company.
Chicago and North Western Railway Company.
Chicago and Rock Island Railroad Company.
Chicago and Southwestern Railway Company.
Chicago, Burlington & Quincy Railroad Company.
Chicago, Kansas, and Nebraska Railway.
Chicago, Milwaukee, and St. Paul Railway Company.
Chicago, Rock Island and Pacific Railroad Company (1866-1880)
Chicago, St. Paul & Fond du Lac Rail-Road Company.
Childs & Hammond.
Cincinnati Southern Railway Company.
Cincinnati, Virginia, and Carolina Railway.
Citti, L. F.
Cleveland & Toledo Railroad.
Cleveland and Mahoning Rail Road Company.