One of the differences between the United States and most countries is that Washington D.C. is not also the most populous city in the country. In most other nations the capital city also serves as the main city of the country and is the most populated.
So your challenge if you choose to accept it is to come up with a way that D.C. is the most populated city in the US in the modern day. Any POD is acceptable.
So your challenge if you choose to accept it is to come up with a way that D.C. is the most populated city in the US in the modern day. Any POD is acceptable.