WIS 19 is a local connector route that links the communities of Waunakee, Sun Prairie and Watertown.

The highway follows two lane surface road for the entire length with the exception of urban multilane arterials.

The route then passed through downtown Madison and followed then WIS 31 (part of the current US 151) to Sun Prairie.

[5] When the U.S. Highway system was implemented, WIS 19's western terminus was relocated to Madison.

In 1947, the eastern terminus was moved to Watertown, the section along US 151 was removed, and the portion between Mazomanie and Sun Prairie was implemented.