Originally Posted by
CO 1E
It takes nowhere near an hour to get from Union Station to DCA - 20-25 minutes at most, depending on which route you take. Even during even rush hour, it would take less than an hour. Also, the Metro only takes 30 minutes (two stops to Gallery Place, then six stops to DCA).
It depends on the time of day as well. You have to do a transfer from red to either blue or yellow. If you go the blue route - likely more than 1 hour.
If you are traveling at night, you may need to wait 20 minutes for the next train if you just miss the last one. Miss the connection plus add travel times, 1 hour is not out of range and maybe not enough. I have spend over an hour going from DCA (blue) to Clarendon (orange) - less stops than to Union Station - in the evening. Hence I always take a cab.