In 1967, during the Vietnam War, Mendez saved the life of his platoon commander, Lieutenant Ronald D. Castille, who would become the Chief Justice of Pennsylvania.

When Mendez' mother became ill and the family's economic situation worsened, his father could not raise him and his siblings, therefore 2 were sent to foster homes and 6 were placed in the Mission of the Immaculate Virgin, an orphanage on Mount Loretto, Staten Island.

After he graduated from his recruit training, he was sent to Marine Corps Base Camp Lejeune, North Carolina to attend the School of Infantry.

Half of his platoon was pinned down in a rice paddy under enemy fire, and Mendez volunteered to lead a squad to assist the pinned-down Marines in returning to friendly lines with their two dead and two seriously wounded men.

Using his own body, Mendez shielded Lt. Castille as he applied a dressing to the wound, he then picked up the Lieutenant and started to carry him to friendly lines, which were more than seventy-five meters away.

In October, 2003 Barraclough and Gallo had finished writing up the new request which had presented only the facts, and added a petition signed by many organizations, Society's, along with many signatures from Staten Island, New Yorkers.

On May 26, 2008, during the Memorial Day celebrations held in San Juan, Puerto Rico,[11] the inscription of the name of Angel Mendez in "El Monumento de la Recordación" (Monument of Remembrance) was unveiled.

The unveiling was done by then Puerto Rico Senate President Kenneth McClintock and PR National Guard Adjutant General Col. David Carrión.

2422), that would permit the naming of the St. George, Staten Island Post Office, located at 45 Bay Street, after Mendez was approved by the US House of Representatives on November 14, 2011.

[14][15][16] Remembered as a "son of Staten Island", in 2017 a military-style ceremony was held by the Catholic Church at Mount Loretto to acknowledge the 50th anniversary of his death.

[17] In July 2019, the South Richmond High School in Pleasant Plains that he attended as a child in Staten Island was renamed the "Sgt.