There's no such thing as an offense of "crossing state lines looking for a fight"...
There are when you're carrying, and aren't licensed to own/carry in IL, and aren't licensed (and not legal) to own/carry in WI.
And,
It is a federal crime to cross state lines or to use interstate facilities to incite or participate in violent rioting
https://theridgewoodblog.net/it-is-...-to-incite-or-participate-in-violent-rioting/
And,
I'd bet there are federal laws against crossing state lines while illegally possessing a firearm.