Eventually recognized by the United States Department of the Army as a fully capable fighting force, the Porto Rico Regiment was reorganized into the Regular Army on 27 May 1908, later becoming the 65th Infantry Regiment. The Regiment would later serve in ground combat. Owning the first shot fired of World War I, campaign credit for its participation in .
World War II, and the Korean War, the Spanish speaking Soldiers of the Regiment served with great distinction living up to their reputation as the "Boriqueeners". It was not until the mass court martial of Company G during the Korean War that the Regiment suffered a devastating blow by the actions of its American Commanders.
In the wake of the Korean War, the Regiment was reorganized into three Infantry .
Battalions, an Artillery Battalion, and a Tank Company. Under the command of Colonel William W. Harris, the Regiment arrived in Pusan, Korea and was attached to the Unites States Army's 3rd Infantry Division under the command of Major General George M. Smythe. It was during their sea journey that the 65th Infantry Regiment adopted the motto "Boriqueeners", this motto amidst other cultural differences was frowned upon by Major General Smythe. Despite ethnic .
differences, the 65th Infantry Regiment fought alongside of the 3rd Infantry Division in notable battles. The Boriqueeners saw combat in the Chosin Reservoir, became the first Regiment to cross the Han River into South Korea during Operation Killer, and named an instrumental force in the defeat of the Iron Triangle. The Boriqueeners quickly earned a reputation for their ability to defeat enemy opposition in the worst arenas of battle. .
On 8 February 1952, Colonel Juan Cesar Cordero Davila was appointed to serve as the Commander of the 65th Infantry Regiment. To the soldiers of the 65th this was a major accomplishment for Puerto Rican soldiers, given the era, Colonel Davila was amongst the very few highest ranking ethnic officers in the Army.
