He served in the Revolutionary War, April 1, 1777 thru the winter of 1782 when he was taken prisoner at the battle of Eutaw Spring, South Carolina.
Jacob was listed as private, 5th Company, 3 Regiment Maryland Line, German, Company commanded by Captain Bosel-Batzel, Regiment commander Colonel Weltner. Jacob was also in battles, Monmouth New Jersey July 1778, Shamong N.J. New Point Virginia, Yorktown Virginia October 1781 when Cornwallis surrendered. (see extensive notes at Findagrave)