Norman Earl Stennrod (1910 - 1971) was a preeminent American mathematician mostly known for his contribution to topology.
Steenrod is famous for having introduced the Steenrod operations , acting on the mod 2 cohomology of any topological spaces, and more generally, on the mod cohomology of any space, for a prime number . His book Topology of Fiber Bundles became a standard reference. With Samuel Eilenberg revolutionised algebraic topology by taking an axiomatic approach in their book Foundation of Algebraic Topology.