General Harbord saw early service with the 10th U.S. Cavalry, where he became allies with General Pershing. In 1902, he was promoted to the position of Chief of the Philippine Constabulary. When the U.S. entered the war, Harbord was chosen by Pershing as the AEF's Chief of Staff in France. In May, 1918, Harbord was re-assigned by Pershing to the Marine Brigade of the 2d Infantry Division, and he and his men successfully halted the Germans at Belleau Wood (6-25 June, 1918). Harbord was promoted major general, and commander of the 2d Division during the counterattacks on Soisson. Pershing then dispatched Harbord to re-organise the AEF Services of Supply in la te July, 1918, which he did promptly and effectively. After the war, General Harbord was promoted to brigadier general in the Regular Army and again appointed Chief of Staff of the AEF, and on return to the U.S. as major general in 1919, commander of the 2d Infantry Division.