There were over 40 evacuation hospital units in the European Theater of Operations, but very few have published unit histories.

A unit history written by an anonymous crewman sometime in the mid-1970s noted:

He took special interest in the unit history of his former command, the 20th Battalion.

They are also responsible for managing collection and compilation of subordinate unit histories.

Brief unit history, including officers' names, regimental strengths, etc.

The center housed many types of intelligence to include unit histories on most allied air forces.

A written test is often also administered, with questions that cover United States Cavalry and unit history.

He assembles a huge array of details to support his mission, drawing heavily from interviews and unit histories.

From September 1939 he had kept a personal diary, which became No.303 Squadron's unit history.

Finally, the unit history of the 1st Battalion, 5th Field Artillery describes the war as occurring solely in 1818.