Claim: Operation Billings commenced on 12 June as 1st Infantry battalions moved progressively north of Phước Vĩnh, then on the morning of June 17 preceded by a moving barrage, the 1st Battalion, 16th Infantry Regiment (founded in 1861), entered LZ X-Ray.
Evidence: The operation commenced on 12 June as 1st Infantry battalions moved progressively north of Phước Vĩnh. On the morning of 17 June preceded by a moving barrage, the 1st Battalion, 16th Infantry Regiment, entered LZ X-Ray. 1861; 159 years ago (1861)