[2] It was added to the State and the National Register of Historic Places in 2006.

[3] Starting with Janesville's founding in the 1830s, most of its early neighborhoods grew west of the Rock River.

After the Civil War, homes were built east of the river too.

Homes in what is now the Jefferson Avenue district were built from 1891 to the 1930s in styles of that period.

Here are some good examples of the different styles, roughly in the order built.