Back in 1917, when the American Expeditionary Force came to France, there were Black (segregated) units included. The French did not see them as Black, just as Americans who came to help in their hour of need. American officers were upset that the Black troops were treated as ‘just troops’ by the French. Gen John Pershing, who led the AEF was fine with Black troops under his command (if you've wondered where he got the sobriquet 'Black Jack', yeah, it was from this - and not intended as a complement).

I'm pretty sure the French fascination with New Orleans style jazz comes from this (which is likely still ongoing; I observed this in the late 70s).