While researching my Great-Great grandfather who served in the Union army in Missouri and was a German immigrant prior to the war, I discovered that he became a naturalized citizen of the U.S. after his service on May 2,1865 which he was required to take the oath of allegiance. In his naturalization record it states that he.."renounce forever all alliance and fidelity to every foreign power, prince, state and sovereignty whatsoever, and particularly to the Duke of Saxe Wiesner..." When was this oath first established and is it still required for foreigners today to be naturalized in this manner?

Robert Caudle