My first live sporting event was Senators vs Red Sox at DC Stadium, 1963...when I returned here for good in 1977 the Senators were of course long gone (plenty of rumours though surrounding the Giants, Astros etc moving here)...but the Washington in which I spent my first 27+ years of my current residency was a non-MLB town and I had no rooting interest in baseball (apart from an occasional nostalgic twinge for the Dodgers, since I had spent much of my childhood in southern California), and I'd satisfy my periodic baseball munchies with sports tourism (Montreal, Boston, old Yankee Stadium, Cincinnati, San Francisco, Minnesota - something I really couldn't do nowadays because of the ghastly airfares). Never supported the Orioles - I don't support Baltimore teams, any more than I support Philadelphia teams or New York teams or Cleveland teams or whatever - because I don't reside there.
Now I've got the Nats and am a charter STH there...may it always remain thus!