 Sergeant First Class Ramos Calero enlisted in the Army in 1941 as an Infantryman. He was assigned to Puerto Rico's 65th Infantry Regiment at Camp Las Casas in San Terce, Puerto Rico. Upon the outbreak of World War II, Calero was reassigned to the 3rd Infantry Division and was sent to Europe with the 65th. He would later fight and serve with the 65th in the Korean War. In 1945, Ramos' company was in the vicinity of Colmar, France and engaged in combat against a squad of German soldiers in what is known as the Battle of Colmar Pocket. Calero attacked the squad, killing 10 of them, and capturing 21 shortly before being wounded himself. Following these events, he was nicknamed One Man Army by his comrades. For these actions, he was awarded the Silver Star. During the Korean War, he returned to the Barrinconiers and fought in Busan, Korea. In Korea, the Barrinconiers played a vital role pushing north. They also protected the perimeter of Hwangnam as the 1st Marine Division arrived after a fighting retreat and helped with the evacuation of the area. They later traveled to Seoul to drive away the Chinese 149th Division. Calero later retired from the Army in 1962. Captain Arlo L. Olson graduated college from the University of South Dakota in 1940 and was commissioned a 2nd Lieutenant in the Infantry through the Army's Reserve Officer Training Corps program. On October 13, 1943, Olson began to lead his men in a drive across the Volterno River in Italy under heavy enemy fire. Through mountainous terrain for 13 straight days, Olson spearheaded the advance of the regiment. Later, it was observed he was one who did not send any of his men into the kind of thing he wouldn't walk into himself. Olson repeatedly led his men in attacks against German forces, personally capturing several enemy positions until he was mortally wounded during a reconnaissance patrol. On October 28, 1943, Olson was posthumously awarded the Medal of Honor for his heroic actions at the Volterno River during World War II. Private Riviera enlisted as an infantryman in the U.S. Army in 1950 and served as a dog-faced soldier during the Korean War with 2nd Platoon Company G, 7th Infantry Regiment. Early in the morning of May 23, 1951, a large hostile force emerged from a dense fog and viciously attacked Riviera and his comrades. Riviera responded by firing his weapon until it jammed. Without hesitation, he threw his rifle down and began to engage the enemy with his pistol and hand grenades. Riviera fearlessly crawled from his emplacement to engage infiltrating enemy soldiers in fierce hand-to-hand combat, holding his position against tremendous odds. He inflicted numerous casualties on the enemy until he found himself without ammunition of any kind except a single grenade. Riviera pulled the pin from the last grenade and waited for the enemy to reach his position. His enemy troops left inside his bunker. Private Riviera activated the grenade with the full knowledge that it meant his almost certain death. Riviera, severely wounded but still alive, was recovered with four dead or dying enemy soldiers around him. Riviera was posthumously awarded the Medal of Honor by President Barack Obama in March 18, 2014.