Series I. Personal Papers is divided into five subseries, which are arranged chronologically. Subseries A. Early Years contains papers belonging to Chamberlain's mother, Cora Lee Chamberlain, including photographs of Chamberlain and his parents (1895-1897) and his mother's diary beginning with her pregnancy (1895-1899). Subseries B. Correspondence with Parents contains weekly letters from Chamberlain to his parents while he was at the University of Washington (1913-1914), at the Massachusetts Institute of Technology (1915-1917), during World War I (1917-1919), and immediately after the war. Subseries C. Correspondence with Wife, Narcissa (1922-1962) contains many letters written to his wife, Narcissa, when they were separated by travel or war. It also contains photographs and clippings. Subseries D. Correspondence with Daughters (1942-1957) contains letters to Narcisse and Stephanie. Subseries E. Other contains a scrapbook made by friends after a visit to California in 1971, his postcard collection (most are blank; many were received from others).