I'm not sure who first used it; but, millennials and other young people started using the term about 15 years or so ago to refer to the Washington DC metro area

I'm not sure who first used it; but, millennials and other young people started using the term about 15 years or so ago to refer to the Washington DC metro area -- District Maryland Virginia. The local media picked up on it and started using it. Old farts like me still think "Division of Motor Vehicles."