The Derby\'s own site says that records before 1937 are \"incomplete\". Considering the Derby winners in 1884, 1919, and 1933 were maidens themselves, there were probably maidens in all three races some years in the distant past, back before they became the \"Triple Crown\". If you want to work on the last 80 years, there were maidens in the Derby in 1998, 1990, 1979, 1971, 1959, 1958, 1950, 1949, and 1945. I couldn\'t find similar lists for the Preakness and Belmont though.