Private Joseph Leonard was one of three Marines attached to the 8th Army Corps, involved in the jungle fighting against the insurgent forces of Emilio Aguinaldo. He was cited for "distinguished conduct in the presence of the enemy in battle" for actions on March 25, 27, 29 and April 4. In this brief period the American forces cleared the insurgents from the vicinity of Manila and captured the rebel capital of Malolos, forcing insurgent leader Aguinaldo's "government" northward into the mountains. The other men awarded Medals of Honor for these actions were Private Howard Buckley and Corporal Thomas Prendergast.