This series contains correspondence, consisting primarily of Union-related business as well as a small amount of personal correspondence, receipts, and letters regarding Gillett's memberships with the Columbia Country Club and National Lawn Tennis Association; correspondence clippings kept by Gillett relating to the trial of Reverend J.D.M. Buckner (a Nebraska pastor who was forced to retire from the Methodist Episcopal Church in 1922-1923) from Emory Buckner, Reverend Buckner's son and partner in the New York law firm Root, Clark, Buckner and Howland; as well as a scrapbook presented as a gift to Gillett in 1932 upon his 40th anniversary with Union, including clippings, correspondence, and notes to Gillett from colleagues and fellow classmates.