Rainbow Division
Report of the Adjutant General of Iowa
For the Biennial Period Ended June 30, 1918
Published by the State of Iowa
Des Moines
The office of the Adjutant General has been a very busy place during the past two years. The United States has been involved in two wars during this period. At the beginning of the year 1917 the Iowa National Guard, with the exception of the Field Artillery, which was mustered out in December, was in Federal service and was on duty on the Mexican Border guarding the border states from invasion. The organizations were returned to their homes early in the year and by March 23, 1917 were all out of active service.
On March 25, 1917 the President again issued a proclamation calling into active service a part of the National Guard from each state, preparatory to entering the World War. In Iowa the First Regiment of Infantry was called into service and placed on duty guarding bridges and munition plants. By July 15, 1917 all other organizations of National Guard had been called into service.On August 5, 1917 all men who had been mustered into National Guard service were drafted into U. S. service. This took the Guard entirely from under the control of the state. By the latter part of August all Iowa units had left the state.
Iowa Guard units sent into the service were all efficient, but it so happened that only one of them, the Third Iowa Infantry (168th U.S. Infantry) experienced any battle field service. This regiment was a part of the 42nd or Rainbow, division, and was a composite organization, composed of the third and parts of the First and Second Infantry regiments. Three-fifths of the enlisted men of the Third, when it left Iowa, had been for some time in the ranks of this regiment. Two-fifths were Guardsmen, transferred from the First and Second Regiments. As a result it was truly a representative Iowa National Guard unit, and its brilliant achievements on the battle fields reflects credit upon the National Guard as a whole.