The 355th Infantry was constituted on 5 August 1917 in the National Army (USA) and assigned to the 89th Division, which was organized under the provisions of the draft law of May 1917. The unit was organized 27 August 1917 at Camp Funston, Kansas with the enlisted coming from the state of Nebraska, junior officers generally coming from Kansas, Missouri, and Colorado, and the senior officers coming from the regular army. The soldiers drilled ceaselessly over the next eight months despite a lack of adequate equipment, dreadful living conditions, and outbreaks of disease in the camps.