This letterbook covers the period March-June 1918. There are also a few letters from August 1918, January-March 1919, and September 1919. Most of the correspondence is by William H. Meadowcroft. Included are letters pertaining to Edison's benzol absorbing plants and other chemical manufacturing interests. Other letters refer to Edison's work for the Naval Consulting Board in Washington, D.C., his extended absence from the laboratory, and his return to West Orange in May 1918. Also included is a letter to a prospective inventor explaining how Edison and his assistants handled the large volume of unsolicited ideas and suggestions received by the laboratory. A letter from April 15, 1918 (not selected) notes that "we have gone out of the motion picture business." Among the correspondents is Leon Ray Livingston, "America's most famous tramp," who published several books under the name "A-No. 1."

The spine is stamped "Letters" and is labeled "Lab. Letters. Mar 1918 Mar.1919." The book contains 698 numbered pages, all but 78 of which are blank, and an index. Approximately 10 percent of the letters have been selected.