The first section of Series I, Correspondence, consists of detailed letters written by the Tongs to family members in the United States while they were serving in the Philippines and Taiwan. These letters provide a good overview of their mission work and family life. The second section of Series I consists of letters written by Walter to his wife and children when he was in the Philippines and they were in the United States following World War II. Davao was devastated during the war and Walter was involved in re-establishing the mission work. These letters provide good documentation of the post-War situation in the Philippines. The third section of Series I contains non-family correspondence to and from the Tongs. Many of these letters are to/from colleagues in the Philippines, and to/from the central office of the American Board of Commissioners for Foreign Missions. The final section of Series I, Circular Letters, includes circular letters of the Tongs and of other missionaries, which provide a good summary of their work.
The Writings and Notes of Series II are primarily those of Walter and Peg Tong. They provide additional documentation regarding their missionary work in the Philippines. The Collected Materials of Series III include detailed field reports of ABCFM mission work in the Philippines. Also included in this Series are materials related to Peg Tong's work with the Committee on Christian Literature for Women and Children in the Mission Field. The archives of this Committee are contained in YDSL Record Group No. 90. Series IV, Personal Items and Memorabilia includes programs and memorabilia from the Philippines and Taiwan as well as biographical information related to the Tongs.