Wilhelm von Steuben received his military training in the Prussian Army serving mostly in Russia. He successively served in the general staff and then was promoted to a Captain at Frederick the Great's headquarters. It is not clear why he was discharged at 33. This left him with the challenge of finding a new position. He became chamberlain at the Petty Court of Hohenzollern-Hechingen which got him the title of Baron. By 1775 he was in need of a new position, tried several foreign armies. When he discovered that Benjamin Franklin was in Paris, he thought that he might be an opening. Franklin sent an introductory letter to Washington which inflated his credentials somewhat, he was advanced travel money and departed Marseilles for Portsmouth, NH.
He arrived at York, Pa (where Congress was), agreed to volunteer his services and was put to work training the men. Since he didn't speak English but he did speak some French, Alexander Hamilton and Nathanael Greene helped him put together a training manual "Regulations for the Order and Discipline of the Troops of the United States," also known as the "Blue Book.". He trained the troops in full dress uniform, introducing a system of progressive training. He also instituted camp sanitation arranging the camps arranged so that the latrines were on one side (preferably down a hill and downwind) and the kitchens were on the other. He was promoted to Inspector General on May 5, 1778. He commanded one of the three divisions at the Battle of Yorktown.