Lamar R. Guernsey was born to Mr. and Mrs. J. J. Guernsey on April 24, 1897. In November 1917, with his family living in Marshalltown, Iowa, Guernsey enlisted in the U.S. Army and was stationed with Co. C, 6th Field Signal Corps out of Fort Leavenworth, Kansas. By June 1918 Guernsey's unit had been transferred to Camp Wadsworth in Spartanburg, South Carolina, in preparation for entry into the war in Europe. He arrived in France on July 23, 1918, and served in the American Expeditionary Forces. Guernsey's unit was stationed at the Vosges front from September 1 to October 12, 1918, and then transferred to the Argonne offensive in reserve. Following the end of the war, Guernsey was discharged from Camp Dodge, Iowa, in June 1919.

Lamar Guernsey's last residence was in Urbana, Iowa. He passed away January 1981.

This collection (1917-2007, undated) contains correspondence of Lamar R. Guernsey shortly before and during his service in the U.S. Army during World War I. Guernsey's two main correspondents are his parents in Marshalltown, Iowa, and Evelyn "Betty" Thompson, a friend who attended Cornell College in Mount Vernon, Iowa, and later was a school teacher in Palo, Iowa.

Guernsey often asked about friends and family back home and shared with his parents what he could about his experiences in the war. He described his overseas trip, the landing, and some of the equipment he carried with him. He also wrote about his experiences in France and shared his views on the French culture.

In his letters to Betty before his enlistment, Guernsey inquired about her college activities and briefly told about his time spent at Iowa State College (University) and the push ball tournament he saw there in 1917. While he served in the military, Guernsey described living conditions, how he spent his Christmas overseas, and some of the places he was able to see and visit while in France. He also related a story about a meal shared with a local French family.

The collection also contains several letters between members of the R. E. J. Thompson family including letters received by Evelyn "Betty" Thompson from other servicemen. Her brother, Cecil, also served in the war and wrote several letters to Betty and to his parents. In a letter to his parents, Guernsey commented that Cecil had been hospitalized following a chemical gassing.

A collection of photographs from the 1930s showing military exercises are included in the papers including a photograph of an unidentified serviceman (possibly Guernsey).  Guernsey's World War I dog tag is located in the artifact collection.

The collection is arranged with biographical information listed first, followed by Guernsey's letters, Thompson family letters, and photographs.