Frederick von Steuben, a Prussian-born aristocrat, was between wars in Europe, so he was willing to come to America, a situation where his skills could be put to good use. The aging (for a soldier) professional needed to distinguish himself, to make a splash, to earn a good pension. Benjamin Franklin beefed up von Steuben’s resume and wrote him a recommendation that the Baron took to George Washington.
Hired by Washington to coordinate his troops, von Steuben found the American military organization very different from European armies. In Germany, you gave an order and it was obeyed. In America, you gave an order and your soldiers wanted to know why you gave that order, so you explained and then the order was obeyed. In Germany you had one soldiering style, while in America each colony had a different style. Undaunted, von Stueben cared about his soldiers, cared about this opportunity to contribute to something real.