The Nuttall Encyclopedia
American general, born in Philadelphia; served in the Mexican War, and in the War of Secession, eventually as commander-in-chief; was author of military engineering works (1826-1882).
Wood, James, ed. Entry for 'M'clellan'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/m/mclellan.html. Frederick Warne & Co Ltd. London. 1900.