Nathan George Shelley, attorney, legislator, and Confederate Army officer, was born in Hawkins County, Tennessee, on February 20, 1825, the son of William Parke and Margaret F. (Etter) Shelley. As a boy he accompanied his family to Talladega County, Alabama, where he assisted his father at his trade as a brickmason. He attended Emory and Henry College in Virginia for one year (1841) before poverty forced him to return to Alabama to work with his father. In 1846, with the outbreak of the Mexican War, Shelley joined Company E of the First Alabama Infantry, commanded by his uncle, Capt. Jacob D. Shelley. After returning to Alabama, Shelley read law at night while working as a clerk in a wholesale grocery business and later as deputy clerk of the circuit court by day. He was admitted to the Alabama bar at Talladega in March 1849. For a time he edited the Talladega Alabama Reporter before being elected in 1851 and 1853 to the Alabama House of Representatives. In 1853 he married Sarah F. Shelley, the daughter of Alabama senator Jacob D. Shelley; they had six children. In the winter of 1854 Shelley visited Texas seeking a healthier climate, and on September 1, 1855, he established permanent residence in Austin. On December 12, 1855, he was admitted to the State Bar of Texas, and in 1856 he established a partnership with W. H. D. Carrington. In 1861 he was elected as a Democrat to represent Travis County in the state Senate.
On March 31, 1861, Governor Edward Clark appointed Shelley manager of the State Lunatic Asylum (later Austin State Hospital), a position he held until he was elected attorney general on February 3, 1862, to replace George M. Flournoy. At the end of his term he served briefly in the Confederate Army of Tennessee, under Gen. Joseph E. Johnston in the Georgia campaign from Dalton to Atlanta. Thereafter he returned to Texas, where he was commissioned a brigadier general of state troops. After the war Shelley signed the oath of amnesty at Georgetown on November 1, 1865, and resumed law practice, this time in partnership with George Fleming Moore. In 1866 and again in 1872 he was elected to the state Senate. In 1873 Shelley delivered the oration at the funeral of Thomas F. McKinney. When Moore was appointed to the state Supreme Court in 1874, Shelley established a partnership with John Hancock. Shelley died in Austin on January 5, 1898. His papers are preserved in the Barker Texas History Center, University of Texas at Austin. He was an active member of the International Order of Odd Fellows.