EDIT- I misconstrued the title and saw it as rank/award...which is why I chimed in with what I wrote below. While not directly answering the question, I'm sure followup questions would have asked this.

Well, First Lieutenant Vernon Baker's actions in early '45 would earn him a Bronze Star, which was upgraded to the MoH in 1997, 52 years after the fact. The dude was involved in an attack on a German castle that sat on a very high bluff, and basically single-handedly solo'd the whole trip, destroying a machine gun position, phone lines, a pair of bunkers and two machine gun posts. That is pretty impressive.

Two other black first lieutenants were also posthumously awarded the MoH for similarly-brave actions, also awarded decades after the fact.

The only black soldier to be awarded the Medal of Honor actually during the war was Private George Watson. The transport he was on in the Pacific near New Guinea was hit by Japanese bombers , and as the ship went down he spent time in the water towing/rescuing men who couldn't swim. He spent too long in the water, was exhausted, and the suction of the sinking ship dragged him down. The MoH was awarded posthumously, of course.

In total, 7 black soldiers of various ranks would wind up winning the award. Watson right after his death, and the other 6 in a ceremony led by President Clinton.

The highest ranking black man during the war itself was Benjamin Davis Sr, who reached the rank of Brigadier General in the US Army in 1940.