These documents consist primarily of letters and postcards from Mina Miller Edison to her youngest son, Theodore. Several of the letters are addressed jointly to Theodore and his older brother, Charles. With the exception of the first itema postcard sent from Atlantic City in early Aprilall of the letters were written after the United States entered World War I and most contain comments about the war and Thomas Edison's wartime research. Included are nine items written aboard the USS Sachem, a 217-gross-ton steam yacht that was taken over by the U.S. Navy in July 1917. During the summer of 1917 Thomas and Mina Edison spent six weeks aboard the ship, cruising various locations on Long Island Sound, including New London, Sag Harbor, and Greenport. The letters contain discussion of accommodations, living conditions, and experimental activities aboard the Sachem. Experimenters whose names appear in the letters include James M. (Jimmie) Burns, William H. Knierim, Bruce R. Silver, and Henry G. Wolfe. In addition to the war-related comments, there are also remarks about Mina's desire for Theodore to enroll at the Massachusetts Institute of Technology in the fall (he did not enter MIT until 1919); an injury to her knee that she sustained while boarding the ship; a visit to the ship by Theodore and Charles in early September; another visit by Theodore at the end of the month; and the wedding of Llewellyn Park neighbors George Wilhelm Merck and Josephine Carey Wall.
The remaining nine items were written from Washington, D.C., where Edison spent four months (October 1917-January 1918) working in an office at the Navy Annex. The letters from this period reflect Mina's growing frustration about the duration of the war and the perceived incompetence of the U.S. government and the Allies, as well as her feeling of being torn between her desire to return home and reunite with her sons and her "duty to be here with Papa." The letters also contain numerous expressions of hostility toward the Germans, including Mina's German-born neighbors in Llewellyn ParkGeorge and Friedrike Merck. One letter voices the hope that a weapon being developed by Theodore with his father's support (a spinning wheel filled with TNT that could be aimed toward enemy trenches) would "mow down those insolent Germans." In another letter, Mina wonders "why isn't it possible to bomb those awful leaders of Germany?"
There are occasional comments in the letters about Madeleine Edison, her husband John Eyre Sloane, and their infant son Thomas Edison (Teddy) Sloane, who were living in Washington, D.C. during the winter of 1917-1918. Many of the letters chide Theodore and Charles for not writing more often. Also included are expressions of regret at not being able to come home for the Thanksgiving holidays. The last letter mentions plans to return to New Jersey for the Christmas holidays, Mina's hope that Edison's lumbago will not delay their departure, and her desire for her husband to continue his experiments in Key West, Florida, after the holidays.