Of particular importance and value are the records of the New York & Texas Steamship Company, 1886-1908, which operated between New York, New York, and Galveston, Texas and correspondence of Clifford D. Mallory with Julius F. Mallory and Carl C. Cutler, ca. 1920-1940, regarding research on the history and genealogy of the Mallory family. Also of significance is correspondence of Clifford D. Mallory with William P. Stephens regarding yachting. There is also considerable correspondence between Clifford D. Mallory and William U. Swan regarding the racing records of the Mallory Family yachts. Between ca. 1939 and 1942 Clifford D. Mallory corresponded with William H. Campbell and Robert R. Campbell in Ayrshire and Glasgow, Scotland, respectively, regarding family matters and the war situation in Great Britain.

Among the letters of well known individuals are the following: Clara Barton to Henry R. Mallory, March 28, 1900; Henry Ward Beecher to Charles H. Mallory, April 24, 1875; Herbert Hoover to Frank C. Munson, June 22, 1928, and August 13, 1932; Edward N. Hurley to Frank C. Munson, July 29, 1919, and to Clifford D. Mallory, July 29, 1919, and June 8, 1922; Franklin D. Roosevelt to Frank C. Munson, September 7, 1928, and June 22 and August 24, 1932; and Woodrow Wilson to Frank C. Munson, August 24, 1918, and May 24, 1919 (signed check). The 1928 Roosevelt letter includes comments on the Presidential campaign, and the Clara Barton letter mentions an incident of the Spanish-American War. The others are all routine items.

Two scrapbooks in the collection were compiled by Rebecca Sealy Mallory to document the Navy career of her son, Clifford D. Mallory, Jr. The correspondence that makes up the bulk of these scrapbooks serves to illustrate the experiences of a young man far from home during World War II. Clifford – also known affectionately as Cip or Cippie to his family – was close to his widowed mother and his sisters, Margaret (Mal) and Barbara (Bobbie), and wrote home at least once a week from his posts in New Zealand and New Caledonia. Because of military censorship he could only hint at his naval duties, but lively descriptions of his surroundings and activities make for interesting reading. While he was posted in New Zealand he met his future wife, Pauline Cropper, and the tale of their courtship and marriage is recorded in these letters. Copies of letters to and from other friends and family members also appear in the collection. Six Sealy cousins and at least one Mallory cousin served in the armed forces, and several are mentioned frequently; George Sealy Livermore, whose name appears most often, was stationed with the Army near Clifford in both New Zealand and New Caledonia. The correspondence has been digitized and transcribed. The transcriptions are faithful to the original correspondence. Ephemera and photographs from the scrapbooks also have been digitized.