There is a John Derr listed in: The German Regiment of Maryland and Pennsylvania in the Continental Army 1776-1781, by Henry J. Retzer. Under German Regiment Privates of the Pennsylvania Company known as Captain Weiser's Company Jul. 1776-Oct. 1776. First vacant company Oct. 1776-?, and Capt. Rice's Company ?-Jan 1781. Derr, John enl. 25 Aug 1776, on duty 3 Oct. 1776 at Philadelphia Barracks. BWCo. BWCo.=Capt. Weiser's (PA) Company 3 Oct. 1776, muster roll;; in PA. Would you please see if there are any DERR names listed.