On Saturday (3/8) I have a 6pm flight to DCA on UA. I won't be getting out of my meetings in the loop until 3:30. Do I have enough time to get to O'Hare, check a bag and get through security?

(I have a Y ticket so I can switch flights but the next flight to DCA isn't until 9 and I don't want to sit around O'Hare for hours!)

(And I know I posted a similar question in the UA forum but have not received any responses so I'm trying this forum!)