The collection includes material from Moses Thatcher Jr., his wife, Sarah "Caddie" Hopkins Thatcher; and their six children: Lettie, Leora, Helen, Martha, Ida, and Moses III. A smattering of material dealing with other Thatcher family members, including Moses Thatcher Sr., Celestia "Lettie" Ann Farr Thatcher, George Washington Thatcher, and others, is also included.

The collection has a major strength in correspondence between Moses Thatcher, Jr., and his wife, Sarah while Moses was on a mission for The Church of Jesus Christ of Latter-day Saints in Great Britain in 1891-1892. The other major portion of the collection focuses on Leora Thatcher, an accomplished Broadway and play actress and radio personality from the 1920s through the 1960's. Found in her papers is a long run of correspondence between Leora and her parents while Leora lived in New York City. Correspondence with Robert Young, The Moroni Olsen Players Repertory Company, and others is also included. Photographs, ID cards from the Screen Actors Guild and Theatre Wing War Service, programs, clippings, and a handwritten autobiography round out the Leora Thatcher holdings.