Better known as "Lafayette", and it's not surprising - his full name was "Marie Joseph Paul Yves Roch Gilbert du Motier, Marquis de Lafayette". His business cards must have been three feet long. Lafayette was a French aristocrat and soldier who decided to join the Revolutionary War, and became one of George Washington's most loyal soldiers. (I'm sure his friends just called him MJ.)
Lafayette came to the colonies in 1777, intent on joining the war effort. So intent, in fact, that he abandoned his post in the French army. When the French army found out his plans, the ship he intended to sail on was seized, and according to one story, Lafayette dressed up in women's clothing to better stow away on another ship heading for the New World. We've all done it.
Lafayette had been promised a place in the army before he left France, but once he arrived Congress became worried that he was just a glory-seeker. To smooth things over, Lafayette offered to work for free - and the ever-thrifty Congress awarded him a commission as a Major General. That may seem a hefty rank for someone who wasn't quite 20 years old, but Lafayette was both rich and a French noble, and at the time Congress was hoping to secure more aid from the French government. It would have made me suspicious. There's no such thing as a free French.
Lafayette was placed as an aide-de-camp to George Washington - probably because that's a French word and it seemed to fit - and the two became good friends. Political connections aside, he was an excellent addition to the army. Lafayette was a natural leader - his first real fight was at the Battle of Brandywine, where he was wounded. Despite that, Lafayette organized and led an orderly retreat - which saved hundreds of lives.
In 1779, Lafayette returned to France, where he negotiated for more troops to be sent to fight in the Revolution - exactly what Congress had hoped for when they hired him. After Lafayette returned to the colonies, he was placed in charge of the French troops, and was responsible for chasing General Cornwallis into Yorktown. There were other people there too. It wasn't just one man chasing another into a town. That would have looked undignified.
After the war, Lafayette returned to France, where he was a leader during the initial part of the French Revolution. Unfortunately for him, he advocated a constitutional monarchy and had to flee when that wasn't enough to satisfy the general populace. He returned to the United States in 1825 to commemorate the 50th anniversary of the revolution - and was greeted by adoring crowds.
In 2002, Lafayette was declared an honorary citizen of the United States, one of seven people to ever receive the tribute. Lafayette didn't even bother turning up to the ceremony.
That's the French for you.