This post is based on--heck, totally stolen from--the 36 Hour series produced by the New York Times. If they send a cease and desist order, well, I’d have to agree that I pretty much copied the idea and would have to comply. Although, technically, this is called the 37 and One Half Hour Series. Click here for Day One. Here for Day Two.
Day Three
Morning: Well, after closing down the bars in the Atlas District, you may want to go ahead and make use of the continental breakfast at the hotel. Sleep in a bit, read the paper and grab that second cup of coffee. This is a half day of sorts, assuming that you'll be getting out of town midday sometime, Take the last few hours to reflect and have little fun.

Just across the driveway of the Jefferson Memorial is the small memorial for another colonial founder, form my home state, George Mason. He exists under the radar for most and only recently got a boost because of the success of the college basketball team at his namesake university. The Mason Memorial and gardens are some of my favorite places on the Mall. Just a bit isolated.
Depending on how much time you have, make the morning a memorial trifecta by walking to the FDR Memorial from the Jefferson. Franklin Roosevelt did not want a massive memorial. He helped lay the cornerstone for the Jefferson Memorial, but later said that upon his death, he wanted a memorial no larger than his desk. And sure enough, after his death, a marble marker, about the size of a large desk was placed on the north side of the National Archives building. It's still there. However, it was not the final memorial to FDR.
The "new" FDR Memorial is large; a winding path through four outdoor "rooms", nearly as long as three football fields. He was and is still the longest serving President, so the size is fitting. Some people skim the elements and quotes while others linger and contemplate. You'll get what you want out of it on you own.
Mid day: After some quite reflection (you'll have to get used to the planes flying out of the airport directly over FDR), spend your last few hours in DC back in the residential city. Georgetown is tried and true. It's a safe space for out of owners looking for familiar brands and logos, bus still has enough unique local commercial entities that it remains stimulating. Visiting, I often feel like a stranger in my own city, but at home at once. Take a cab there or give a go at navigating the bus system to get to M St NW above 29th Street. Try the Circulator.

Well, that's it. 37 and one half hours on Washington DC. Hardly fair, but if you plan ahead you can see a lot of the District in a short amount of time. And maybe you'll plan another visit. Hmmm... that will call for Another 37 and One Half Hours in DC post. Not for a while though, this was a lot of work!