Historians have been most unkind to Napoleon - he was the ally of the USA and had some kind of personal magnetism about him; the Brits refused to allow him to live in England as his brother did, had to pull a regiment of British troops off St Helena that were guarding him as they had become too attached to him, even prosecuted a British admiral for plotting to rescue him from exile. This from the troops that fought against him! As one of the British sailors that carried him from France to St Helena stated, if people could come to know him as they had (in that short time aboard ship) they would never wish to harm a hair of his head. Not exactly the ogre or tiger depicted by the Brit press.
The Franco-US friendship was not limited to the Napoleonic wars period as our amigo Real de Tayopa pointed out, France was allied to the US in our revolutionary war, and during the French revolution, land was purchased and a settlement built in the wilds of PA for Marie Antoinette and her followers, so it would hardly be strange if some treasures got moved to the US in that time period.
Please do continue,
Oroblanco