a view of mathematics that was just vastly different ... That was a very important experience for me. So after that I took a lot of courses from Hille" including, in his sophomore year, graduate-level real analysis. "Starting with that course with Hille, I began to have some sense of what mathematics is about." While at Yale he competed three times (1940, 1941 and 1942) in the recently founded William Lowell Putnam Mathematical Competition, always placing among the top five entrants in the country (making him the second three-time Putnam Fellow). After the Japanese attacked Pearl Harbor during his senior year, Gleason applied for a commission in the US Navy,<ref name="secret-life">. </ref> and on graduation joined the team working to break Japanese naval codes. (Others on this team included his future collaborator Robert E. Greenwood and Yale professor Marshall Hall Jr.) He also collaborated with British researchers attacking the German Enigma cipher; Alan Turing, who spent substantial time with Gleason while visiting Washington, called him "the brilliant young Yale graduate mathematician" in a report of his visit. In 1946, at the recommendation of Navy colleague Donald Howard Menzel, Gleason was appointed a Junior Fellow at Harvard. An early goal of the Junior Fellows program was to allow young scholars showing extraordinary promise to sidestep the lengthy PhD process; four years later Harvard appointed Gleason an assistant professor of mathematics, though he was almost immediately recalled to Washington for cryptographic work related to the Korean War. He returned to Harvard in the fall of 1952, and soon after published the most important of his results on Hilbert's fifth problem (see below). Harvard awarded him tenure the following year. In January 1959 he married Jean Berko whom he had met at a party featuring the music of Tom Lehrer.<ref name="lww">. </ref> Berko, a psycholinguist, worked for many years at Boston University. They had three daughters. In 1969 Gleason took the Hollis Chair of Mathematics and Natural Philosophy. Established in 1727, this is the oldest scientific endowed professorship in the US. He retired from Harvard in 1992 but remained active in service to Harvard (as chair of the Society of Fellows, for example) and to mathematics: in particular, promoting the Harvard Calculus Reform Project and working with the Massachusetts Board of Education. He died in 2008 from complications following surgery. Teaching and education reform Gleason said he "always enjoyed helping other people with