Swamps

Before his presidency was over, Adams was compelled to leave Philadelphia to set up his government shop in the new, barely begun capital of Washington, where the vast, endless streets, which mostly contained no buildings of any kind, were unpaved, muddy cesspools in winter, waiting for summer to transform them into mosquito-infested swamps. Washington, in fact is built on a swamp and, then and now, specialized in gigantic cockroaches, which terrified Abigail, Adam's wife.

Paul Johnson "A history of the American People".