Saunders Mac Lane (1909 - 2005) was an American Mathematician. After earning an MA from the University of Chicago in 1931, he attended the University of Göttingen?, 1931–1933, studying logic and mathematics under Paul Bernays?, Emmy Noether? and Hermann Weyl?. He spended most of his career at the University of Chicago.
Saunders Mac Lane is the cofounder of category theory with Samuel Eilenberg, with whom he collaborated on group homology; they introduced Eilenberg-MacLane spaces? in topology. Mac Lane introduced products and coproducts in category theory. He also introduced monoidal categories and symmetric monoidal categories.
He initiated the North American School of Category Theory with Eilenberg.