Looks like the ATC delays trickled down to DCA this morning. My morning flight 1545 to IAH got delayed by nearly 4 hours because of crew rest. WHen I checked where the plane had come from - ORD. It was delayed by 6+ hours last night and got into DCA only at 2am. The reason for that delay ATC! The flight is about to fly in 2 minutes (I got my res canceled for free) and the plane is 90%+ empty.