The Illinois Republican Party was formed May 29, 1856, at the Bloomington Convention in Major’s Hall in Bloomington. The party’s establishing members came out of the state’s old Whig Party once its ex-members joined efforts with several local political groups. Among those factions was, notably, the Independent Democrat group of Chicago that played a significant role in the election of James Hutchinson Woodworth as mayor in 1848.

Illinois Republican Party

Illinois Republican Party

In those early days, the state’s Republican Party included many members from the world of commerce who embraced the notion of Chicago as a portal to the western territories of the nation.

Party members soon identified the anti-slavery sentiments they had in common – a position that differentiated them from more established parties on the East Coast. Many party members failed to win statewide office or win election to the U.S. Congress because of this view. However, the anti-slavery position later helped several candidates gain offices such as the Governorship of Illinois and – during the 1850s – a term in the U.S. House of Representatives for former Chicago Mayor Woodworth.

It was May 1860 when the Illinois Republican State Convention took place in Decatur. At this significant event Abraham Lincoln received his first endorsement for the presidency.

The party leadership wanted to hold their convention in Chicago, but the city then didn’t have a meeting hall large enough to accommodate the event. As a solution, a temporary wood-frame assembly hall that could seat about 10,000 people known as the “Wigwam” was selected as the convention site. The convention drew a lot of interest from local citizens who filed their way into the building to take part in the event. Delegations were seated according to state, although there was no representation for the slave states of North Carolina, South Carolina, Tennessee, Arkansas, Georgia, Alabama, Mississippi, Louisiana, and Florida.