The 27th Infantry Regiment, nicknamed the "Wolfhounds", is a regiment of the United States Army established in 1901, that served in the Philippine–American War, in the Siberian Intervention after World War I, and as part of the 25th Infantry Division ("Tropic Lightning") during World War II, the Korean War, and later the Vietnam War. More recently the regiment deployed to Afghanistan for the second time, following two deployments to Iraq. The regimental march is the Wolfhound March.
The 1st Battalion arrived in South Vietnam in January 1966. During their 5-year stay in Vietnam, the Wolfhounds were considered one of 25th Infantry Division's most effective units, earning a Valorous Unit Citation in 1967. Primarily operating from Chu Chi in the Tay Ninh Province, the Battalion participated in Operation Attleboro, Cedar Falls, Junction City, the '68 and '69 Tet Counter-Offensives, and the 1970 invasion of Cambodia. One of last of the 25th Infantry Division's units to depart Vietnam, the Wolfhounds arrived home in Hawaii in April 1971.