The Iowa in the Civil War Message Board

Iowa vs Illinois, CW era

I have come across a diary of an Iowa soldier. While in Muscatine, he talks about going across the river to "suckerdom." I am assuming this is some sort of derogatory reference to Illinois. Would that be a proper assumption? Was there any sort of rivalry between the two states at that time? Did Iowa citizens refer to Illinois citizens as suckers? Any local input would be appreciated.