US Highway 110
Early in the life of the US Numbered Highway System, there existed numerous intrastate US Highways, and ones less than 300 miles in length. Now, AASHTO guidelines are for state highways to replace US Routes less than 300 miles in length, unless they cross a state line.
One of these highways was US-110, which ran along what is present-day US-45 (US-41 during US-110's life) from Oshkosh, WI north to US-10, or present day WI-110/WI-96. It was only 40 miles in length, and thus an early candidate for removal.
Image and history: Michael Summa via USEnds
Wisconsin Route 110 supplanted the US Highway in 1940, but due to extensions and truncations of WI-110, most of the route does not follow the Old US-110 alignment from Oshkosh to Fremont, WI. WI-110 now runs from Fremont, WI to Marion, WI.