For the next two months, the Herbert Hoover Presidential Library and Museum in West Branch will be hosting a traveling exhibit, “America’s Road: The Journey of Route 66”. Stories/press releases: West Branch Times, Mason City Globe Gazette (with photo).
The Hoover museum usually does a good job of finding temporary exhibits that are at least tangentially connected to Herbert Hoover, Lou Henry Hoover, and their era in general. Hoover was secretary of commerce in 1926, when the US highway route numbering system was created and implemented nationwide. (Hoover is also the last Cabinet secretary elected president.) At the time, the Bureau of Public Roads was a subdivision of the Department of Agriculture, since its earliest roots went back to construction in national forests. (The related quirk of history: The Forest Service is a subsidiary of Agriculture and not Interior!)