[4][5] The RPI was founded on an anti-slavery platform in 1856 by citizens dissatisfied with the existing Whig and Democratic Parties.

Samuel J. Kirkwood, abolitionist and later Iowa's Civil War governor, is credited as one of the principal founders.

Another principal founder was Edward Russell, an outspoken abolitionist editor who later turned the Davenport Gazette into an award-winning Republican newspaper and one of the largest dailies in Iowa.

[6] At the Republican State Convention in 1865, Russell introduced the resolution declaring negro suffrage in Iowa and carried it by a decisive majority.

[7] His more famous son, Charles Edward Russell, went on to found the National Association for the Advancement of Colored People (NAACP).

In 1932 electoral frustration with the Great Depression and Prohibition led to the re-emergence of the Democratic Party in Iowa.

Since 1979, the RPI has held a straw poll in Iowa in each year preceding a presidential election, except when there is a Republican incumbent.

Iowa holds a powerful position in that process because it can serve as a sounding board for the strength of a candidate's campaign.

In particular the Iowa Republican Caucuses hold the most power when either the GOP is not the party in the presidency or an incumbent is not on the ballot.

In 2000 with a potentially heated nomination fight between then Texas Governor George W. Bush and Arizona Senator John McCain, Bush, who carried the state with 41% of the vote, set the tone for his campaign and set up a successful run for the Republican nomination and the presidency.