one of the division's five battle groups. On 24 June 1960 the 1st ABG, 503d Infantry was relieved from assignment to the 82d Airborne Division and assigned to the 25th Infantry Division in Hawaii, remaining there until 1 July 1961 when it was relieved from the division as it traveled to Okinawa. The ABG was accompanied by Battery C (Abn), 319th Artillery, later reorganized and redesignated as HHB, 3d Battalion (Abn), 319th Field Artillery. On 26 March 1963 it was assigned to the newly activated 173d Airborne Brigade, and shortly thereafter it was reorganized and redesignated as the 2d Battalion, 503d Infantry on 25 June 1963. Additionally, on 26 March 1963 the 1st ABG, 503d Infantry was relieved from assignment to the 82d Airborne Division, assigned to the 173d Airborne Brigade and subsequently reorganized and redesignated as a battalion as well. Further Service by Regimental Elements Vietnam War In May 1965, two battalions of the 503rd Infantry deployed as part of the 173rd Airborne Brigade to Vietnam as the first major U.S. Army ground combat unit to be deployed, joined later by 4-503rd Inf and 3-503rd Inf (bearing the lineages of the former Company D and Company C, 503rd PIR, respectively). During its six years in Vietnam, the four battalions of the 503rd participated in fourteen campaigns, earning two more Presidential Unit Citations and a Meritorious Unit Commendation. The 2nd Bn (Abn), 503rd Inf participated in the only combat jump of the war during "Operation Junction City" in 1967. It redeployed to the U.S. in July 1971, having the distinction of being one of the last units to leave Vietnam. Following the return of the 173rd Brigade (Separate) to the U.S. was its inactivation when its assets were used to form the 3rd Brigade (Airborne), 101st Airborne Division (Airmobile). The 1-503rd was relieved from the 173rd effective in August 1971. The 1-503rd was deactivated and 4-503rd was reassigned as 1-503rd 173rd Brigade Separate and on 14 January 1972 reassigned to 3rd Brigade, 101st Airborne Division (Airmobile). The 2-503rd continued as 2-503rd, 173rd Airborne Brigade (Separate)and on 14 January 1972 relieved and reassigned as 2-503rd 3rd Brigade, 101st Airborne Division (Airmobile). The 3-503rd was relieved and reactivated as 3rd-187th 173rd Airborne Brigade (Separate) and on 14 January 1972 reassigned to 3rd Brigade, 101st Airborne Division (Airmobile). The 3rd Brigade, along with other supporting division units, saw its jump status terminated on