Gouverneur K. Warren
William P. Carlin was born at Rich Woods in Greene County, Illinois, and educated in the local schools. His parents were William B. Carlin (1804-1850) and Mary Carlin (née Goode, 1805-1888). His uncle Thomas Carlin, a Jacksonian Democrat and veteran of the War of 1812 served as Illinois' governor when William was a boy. He received an appointment to the United States Military Academy in West Point, New York, and graduated in 1850, ranking 20th out of 44. Among his classmates were future six Civil War generals, including Gouverneur K. Warren and William L. Cabell.