Does anyone have any link for people to read about this “foreign soil” thing? I’ve been looking and can’t find anything.

The .gov website says:

Washington, DC, isn't a state; it's a district. DC stands for District of Columbia. Its creation comes directly from the US Constitution, which provides that the district, "not exceeding 10 Miles square," would "become the Seat of the Government of the United States."

Other websites say stuff about it becoming a corporation in 1871 but nothing about it being foreign soil.

Edit: just want to be clear, fuck DC and all the corrupt assholes in it, just wanted clarification on the foreign soil part.