The correct answer to this open question is the following.
Two foreigners who were present with the Americans at Valley Forge were Baron Friedrich Wilhelm von Steuben and Marquis Lafayette. They helped the Americans troops to fight the British Army during the Revolutionary War.
Baron Friedrich Wilhelm von Steuben was a Prussian Military Officer that accepted the invitation of General George Washinton, leader of the Continental Army, to train the American troops in order to improve their battling skills. His training was of so much help for the American Army. Marquis Lafayette was a French military officer who decided to fight with the American troops during the American Revolution.
