In company with members of the Fifth, Thirteenth, Twenty-Third Companies and Marine and sailor detachment from the , Sergeant Iams participated in the attack on Fort Riviere, Haiti, November 17, 1915. Following a concentrated drive, several different detachments of Marines gradually closed in on the old French bastion fort in an effort to cut off all avenues of retreat for the Caco bandits. Approaching a breach in the wall which was the only entrance to the fort, Sergeant Iams unhesitatingly jumped through the breach despite constant fire from the Cacos and engaged the enemy in a desperate hand-to-hand combat until the bastion was captured and Caco resistance neutralized.