I searched in AA, UA and Midwest forums and can't find the answer so I'm hoping someone with more ORD experience can chime in here:

Is there any way to stay airside to make a connection between AA flight arriving at Terminal 3 K concourse and a UA flight leaving from Terminal 1 C concourse? I've got a 2 hr connection time but really don't want to do the security circus twice if it's avoidable

LBsquared