The diary, May 27, 1865 - June 29, 1865, was written while Joseph G. Lorimer was with the United States Christian Commission in the Washington, D.C. area. He visited soldiers in hospitals, prisons, and encampments, and preached and distributed "religious papers", writing paper and envelopes, and clothing.

Joseph G. Lorimer (1833-December 21, 1910) was born in Canada of Scottish parents. He studied theology at the New Hampton Institute, Fairfax, Vermont. On September 30, 1862 he married Almira Hale, a music teacher at the Institute. He served as pastor in Derby, Vermont for 16 years. In 1877 he became pastor of the Georgia Plain Baptist Church, Georgia, Vermont.