Eurofed
Banned
40 states!! By 1865 (assuming this civil war is done by then). Plus in OTL by 1965 Oregon, Cali and Nevada where already states, my guess is that with western migration ITTL Colorado (which has already been hinted) and an Oregon state should become states soon.
With so many stars so early on there might be the possibility of altering the flag to a more unifying national symbol. Not just so it does not look overcrowded but so people can relate to it.
Honestly if you have 40 by 1865 and this becomes an ameriwank then you could end up with over 80 states, try to fit that into a flag in an elegant way.
Amateurs.
My "United States of the Americas" (and Oceania, in the far future) already clocks at 58 North American, Caribbean, and South American states, in 1842, and most of the North, West, and Mexico has still to be settled into states, not to mention future conquests.