There was no Union game at Baltimore yesterday on account of the illness of two of the Baltimore Union nine.-St. Louis Globe-Democrat, September 4, 1884
Really? You have a couple of guys sick so you cancel the game? You couldn't find two half-way decent baseball players in all of Baltimore? You either find a couple of players or you forfeit the game. That's how things are done in a major professional baseball league.
I had an open mind about this at one point but there is no way to look at the evidence and come to any other conclusion except that the UA was not a major league. And, really, it was a bit of a joke.