Originally Posted by
Snuggs
Below is a post from 2018. I doubt the situation has improved.
Originally Posted by
monsieurcumulus
....No storage in ORD and Hilton (and any hotels) will usually refuse to check if you don't stay there. Union Station has a bag check but you need a train ticket. You may want to look at bagnb.com
The following is is a cross post of a reply to a similar post in the UA forum. The post I reference is from the end of May 2021.
Take a look at this
thread in the US - Midwest forum, specifically post #431. It is one of the long layover threads and there are people who have posted on the thread saying they were able to do a "left luggage" service at the Hilton (directly connected to the domestic terminals) for a fee. .
This information is a couple of years old so YMMV.