The Sara Boddie Downer Papers consist of correspondence, writings, scrapbooks, biographical information, and photographs. Of particular significance are letters that Downer wrote between 1918-1986. Many of the documents are copies of letters that Downer wrote for the Woman's American Baptist Foreign Mission Society and sent to her Mount Holyoke College classmate, Ruth Sonn ("Sonny") Fritts; and two Mount Holyoke faculty members, Mildred Allen and Margaret Ball. The collection also includes several personal letters that she sent to Fritts and Ball. These letters chiefly describe Downer's life and work in China from 1920-1951. They reflect her activities at West China Union University in Chengdu, China, where she was a teacher and housemother, and her travels in China; they frequently include comments on political events, such as the Sino-Japanese Conflict, World War II, and the rise of communism in the country. Later letters describe her work in the Chung Chi College in Hong Kong, 1955-1962, and her activities in retirement. Downer's correspondence also includes letters, 1919-1946, written by Mary E. Woolley, President of Mount Holyoke College. The letters discuss events at the College such as the construction of new buildings, Woolley's trip to China and Japan in 1921, and world events. Downer's close relationship with Mount Holyoke's president is reflected by two scrapbooks of clippings, notes and tributes relating to Woolley that she complied between ca. 1918 and 1955. Downer's papers also include two laboratory manuals in Chinese that she wrote in 1930, and her informational brochure about the West China Union University, ca. 1938. Rounding out the collection is biographical information, ca. 1921-1988, and photographs, ca. 1930-1955, which chiefly relate to her life in China.

Arranged in 5 series: Series 1. Correspondence. Series 2. Writings. Series 3. Scrapbooks. Series 4. Biographical Information. Series 5. Photographs.