If you mean defeat of the constitution, and continuance of the Articles of Confederation, the American union would have totally dissolved before 1790.
Had that happened, there is no telling how the European powers would have divvied up North America.
That was the fear mongering. How has the federation worked out so well? The US saddled with massive debt, a massive entitlement culture, and an Executive that acts like a monarchy. The US would have been better off as a Confederation without an Executive, clearly.