Easy connection, DCA is one of my favorite airports and now that all gates are post-security it's even easier and more spaced out, the only curveball would be any unforeseen delays with your flight to DCA, for peace of mind would recommend selecting a seat closer to the front of the aircraft even if there is an extra cost, this guarantees that you will be one of the first few to exit the plane after First Class. As mentioned by pp, if your flight arrives on time, you should have enough time to use the restroom and perhaps even buy a quick to-go snack or beverage.