[1] The post office was built as part of the Works Progress Administration of the New Deal.

Like many government buildings of the New Deal era, it has a modernist design with minimal decoration.

The interior features a relief sculpture by Jefferson Greer titled Discovery of the Northern Waters of the Mississippi.

The work, which was commissioned by the Public Works Administration in 1938, depicts Jacques Marquette and Louis Jolliet discovering the confluence of the Mississippi River and Wisconsin River near modern-day Prairie du Chien.

Greer was a Milwaukee-based sculpture who assisted in the design of Mount Rushmore; the Prairie du Chien relief is his only post office work.