Question

This political Party was formed in Wisconsin in the 1850s and was largely supported by Northerners who favored its anti-slavery policies.

Answer 1

The Republican Party.

It was originally more progressive and anti-slavery (for example, Abraham Lincoln was the first Republican President). Over time, the Democratic Party became the more progressive party as 1) blacks shifted away from the Republican Party following the failure of Reconstruction in the South and 2) the Republican party aligned itself more with big business in later years.