Is there a way to find the Oath of Allegiance taken by my ancestor: Gabriel L. Page (also sometimes listed as G.L. Page/Globe L. Page), 18th Texas Calvary, Co.B, captured at Arkansas Post Jan 1863, & taken to Camp Douglas. Involved in prisoner exchange at City Point, VA, 7 April 1863. He eventually rejoined his unit and fought in the Battle of Chickamauga, being wounded in the leg, and undergoing an amputation. Have Compiled Service Record, but seem to be missing the Oath of Allegiance. Thanks.