Who was the first Marine to win the Medal of Honor?

The first Marine to win the Medal of Honor was indeed Corporal John Mackey. He earned this prestigious award during the Civil War for his acts of bravery and heroism as a member of the Marine Corps. The Medal of Honor was created during the Civil War, and Mackey's actions distinguished him as a notable figure in Marine Corps history. His recognition set a precedent for the valor exhibited by Marines who would follow in various conflicts throughout the years.