Abstract The Mastiff Club of America (MCOA) collection contains breed research, clippings, and photograph files dating back to 1890; club administration files holding a wide variety of club records dating between 1938 and 2008; catalogs, premium lists, and photographs for events beginning with the club's first independent specialty in 1983; a broad swath of Mastiff-related publications released by the club, its affiliates, and other regional and international associations devoted to the breed...