Urgh, our sympathies to 10,000’s of you who were impacted by the computer malfunction at the air traffic center at Leesburg VA, which resulted in delaying all incoming and outgoing flights at all Eastern airports.
The issue happened around 9:45 am and was fixed about 4:00 pm. From the Washington Post:
The Washington facility and other control centers dictate routing once airplanes reach an altitude above about 20,000 feet. (Once they go below that altitude, they are directed to airports by controllers at Terminal Radar Approach Control Facilities called TRACONs. For final approaches and takeoffs, they are directed from control towers.)
When the Washington control center stopped functioning, the TRACON serving National and BWI had no one it could hand flights off to as the planes reached cruising altitude. And East Coast flights — for example, a Miami-New York flight — were delayed or routed around the airspace controlled by the Washington center.
So there you have it. At least you know why you were screwed.
The joys of travel.