SaundersMacLanewasbornonAugust4，1909inConnecticut.HestudiedatYaleUniversityandthenattheUniversityofChicagoandatG6ttingen，wherehereceivedtheD.Phil.in1934.HehastaughtatHarvard，Cornel1andtheUniversityofChicago.MacLanesinitialresearchwasinlogicandinalgebraicnumbertheory（valuationtheory）.WithSamuelEilenberghepublishedfifteenpapersonalgebraictopology.Anumberoftheminvolvedtheinitialstepsinthecohomologyofgroupsandinotheraspectsofhomologicalalgebra-aswellasthediscoveryofcategorytheory.HisfamousundergraduatetextbookSurveyofmodernalgebra，writtenjointlywithG.Birkhoff，hasremainedinprintforover50years.MacLaneisalsotheauthorofseveralotherhighlysuccessfulbooks.