George David Birkhoff was one of the top American mathematicians of his generation. He made valuable contributions to the theory of differential equations, dynamical systems, the four-color problem, the three-body problem, and general relativity. Today, Birkhoff is best remembered for the ergodic theorem. The George D. Birkhoff House, his residence in Cambridge, Massachusetts, has been designated a National Historic Landmark.

Overisel Township is a civil township of Allegan County in the U.S. state of Michigan. The population was 3,113 at the 2020 census.