The Harlem Hellfighters was a Black US infantry unit which was the first US unit to fight in WWI spending more time in combat than any other US unit.

The 369th Infantry Regiment consisted of African Americans and Puerto Ricans and was known for being the first African-American regiment to serve with the American Expeditionary Forces during World War I. The regiment was nicknamed the Harlem Hellfighters. The nickname "Hell Fighters" was given to them by the Germans due to their toughness and that they never lost a man through capture, lost a trench or a foot of ground to the enemy. While overseas the 369th Regiment made up less than 1% of the soldiers deployed but were responsible for over 20% of the territory of all the land assigned to the United States. While in the United States, the 369th Regiment was never treated like similar all white units. They were subject to intense racial discrimination. This regiment suffered considerable harassment by both individual white American soldiers and even denigration by the American Expeditionary Force headquarters which went so far as to release the notorious pamphlet Secret Information Concerning Black American Troops, which "warned" French civilian authorities of the alleged inferior nature and supposed rapist tendencies of African Americans. In France, the 369th was treated as if they were no different from any other French unit. The French did not show hatred towards them and did not racially segregate the 369th. The French accepted the all black 369th Regiment with open arms and welcomed them to their country. The French were less concerned with race than the Americans.