Long Island Rail Road.
Lorenz, William, 1826-1884.
Louisville and Cincinnati Branch Railroad.
Louisville, New Albany, and St. Louis Air Line Railway Company.
Louisville, New Orleans, and Texas Railroad.
Lucas, Fielding, Jr., 1781-1854.
Lucas, William B.
Lyons, C. J.
Mahone, William, 1826-1895.
Manassas Gap Railroad Company.
Marietta and Cincinnati Railroad Company.
Marietta and Pittsburgh Railroad.
Maury, Matthew Fontaine, 1849-1886.
McAlpine, William J. (William Jarvis)
McLellan, David, approximately 1825-
McMinn, J. M. (Joseph M.)
Memphis and Little Rock Railroad.
Memphis and New Orleans Railroad.
Mendel, Edward, 1827-1884.
Metropolitan Railroad Company (Georgetown, Washington, D.C)
Michigan Southern Railroad.
Middleton, Wallace & Co.
Millard, B. F.
Miller & Co.
Miller, Edward, 1811-1872.
Milwaukee and Horicon Railroad.
Milwaukee and St. Paul Railway Company.
Milwaukee and Superior Railroad Company.
Mine Hill and Schuylkill Haven Railroad Company.
Minor, Daniel K.
Mississippi Valley Railroad.
Mitchell's Map Publication Office.
Mitchell, S. Augustus (Samuel Augustus), 1792-1868.
Mobile and Northwestern Railroad Company.
Mobile and Ohio Railroad Company.
Moore, W. C.
Morgan, Charles, joint author.
Morris, Ellwood, 1813?-1872.
Morris, Thomas A. (Thomas Armstrong), 1811-1904.
Morrisse, James A.
Morton, A. C. (Engineer)
Mota, Alb von.
Mowry, Sylvester, 1830-1871.
Mueller, J. (John)
Nash, L. S.
Nashville, Chattanooga, and St. Louis Railway.
Nesbitt (Geo. F.) & Company.
New Hampshire. Railroad Commissioners.
New Haven, Middletown, and Boston Railroad.
New Orleans and Ohio Railroad.
New Orleans, Mobile, and Chattanooga Railroad.
New Orleans, Opelousas, and Great Western Railroad Company.
New River Railroad Company.
New York & Oswego Midland Railroad.
New York Central and Hudson River Railroad Company.
New York and Erie Railroad Company.
Nicholson, W. L.
Noble, C. E., active 1856.
Norfolk and Cincinnati Railroad.
Norfolk and Petersburg Railroad Company.
Norfolk and Western Railroad Company.
Norfolk, Albermarle, and Atlantic Railroad.
Norfolk, Wilmington, and Charleston Railroad.
Norris, William (Engraver)
North East and South West Alabama Railroad.
North Pennsylvania Railroad Company.
Northern Pacific Railroad Company.
Northern and Southern West Virginia Railroad.
Norton, J. A.
Ohio Southern Railroad.
Ohio and Pennsylvania Rail-Road Company.
Okelomski, F. A.
Old Colony Railroad Company.
Olmstead, S. R. (Samuel R.)
Orange and Alexandria Railroad Company.
Oregon Railway and Navigation Company.
Osborne, R. B. (Richard Boyce)
P.S. Duval & Co.
Pacific and Atlantic Railroad Company.
Palmer, W. R. (William R.), -1862.
Palmer, William Jackson, 1836-1909.
Parge, H. R.
Parke, John G.
Parker, Nathan H. (Nathan Howe)
Parrott, George B.
Paterson and Dover Railroad.