Lots of possibilities
I could see the colonies NOT reaching agreement on a constitution and going off into 2-3 different groups, with 1 or 2 trying it alone.
In that case, they'd be weaker vis-a-vis England and would probably never resist British actions that led to the war of 1812. UK would probably grab some more disputed lands and some of the colonies might reclaim land they'd ceded. I assume France would try to sell pieces of the Louisiana Territory to different takers -- some of the colonies, Spain, etc.
The colonies would, in general, expand West, but it would be slower and there might be some areas they could never take. Also, some areas that are colonized by the states/state groups might then break away from their founder.
So, where the US is, you might have 3-4 colonial-derived confederations, some areas retained by Britain that become part of Canada, some areas retained by Spain (that eventually go independent), a few areas not sold by France (New Orleans) that are ceded to Britain, a larger Mexico, and maybe a few Native American nations that organize enough to establish (and maintain) boundaries.
In that TL, eventually you'd have wars between some of those nations, but fear of the others would limit the scope. Those state confederations would likely be split along slavery lines, so the civil war wouldn't erupt on that score. You might still have Texas helped to independence, but you'd probably never have an invasion of Mexico. With various neighboring countries, these states aren't protected by two oceans and don't become major naval presences or get into overseas adventures (Phillipines, Cuba, etc). When WWI comes along, you could see some of them, potentially on either side, but many stay neutral; likewise WWII.
So, a very different North American, indeed.