Hancock was elected to the Texas legislature as a Unionist in 1860. During the Civil War he was an avowed Union man but took no part in active hostilities. In March 1861 as a member of the legislature he declined to take the oath of allegiance to the Confederate States and was expelled from the legislature. He practiced in the state courts but refused to conduct any legal business in the Confederate courts or in any way to recognize their validity or constitutionality. In 1864 he left Texas for Mexico, where he remained for several months. He was in New Orleans at the time of Robert E. Lee's surrender, whereupon he returned to Texas.
Hancock was a member of the Constitutional Convention of 1866 and was conspicuous in that body for his efforts in favor of reconciliation and the restoration of the Southern states to the Union. He declined nomination to Congress in 1870 but subsequently ran on the Democratic ticket and was elected to the Forty-second Congress; he served from 1871 to 1877. He returned in the Forty-eighth Congress, 1883-85. He supported the Indian peace policy of the Grant administration, which called for placing Indians on reservations under government supervision. Hancock married Susan E. Richardson in November 1855. He was a member of the Episcopal Church. He died on July 19, 1893, in Austin, and was buried in Oakwood Cemetery.
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