Vacation in DC with a toddler?

For the most part, I think it's stroller friendly. You will do a lot of walking. Note that the Capitol, Smithsonian down to the Lincoln Memorial is going to take several days. Not sure about the circualtor bus, as I never rode it. The Metro is very stroller friendly. Elevators at all of them and the gap between the train and the platform is only an inch or so wide. I brought my niece around, several years ago, in a stroller and had no problems.