The 173rd Infantry Brigade was constituted on 5 August 1917 as an infantry brigade and organized on 25 August at Camp Pike, Arkansas, as an element of the 87th Division along with the 174th Infantry Brigade. The brigade deployed to France along with the rest of the division in September 1918, but it did not participate in any campaigns and never saw combat, instead being utilized as a pool of laborers and reinforcements for frontline units.