1. Most of the states break apart due to various issues after the revolutionary war. They create a Holy Roman Empire or EU like system or something that's a mix of the two. They often fight among themselves but ally together when threatened by a European or outside power. Settlers create new nations that join the system as they expand west or some join already founded nations. Settlers from the colonies still expand outside the original 13 colonies. They even go to European colonies and other nations in America which leads to them creating some new republics in these areas when they rebel. You have New England, Vermont, New York, Pennsylvania, New Jersey, Maryland/Delware, Virginia, Carolinas, and Georgia as the first ones. Florida later becomes a republic when it rebels from Spain and same for French Louisiana.
2. South barely gets all slave states besides Maryland and Delaware to secede. New England also secede due to its own issues with the union around the same time. They both win the war quickly due to mismanagement by union leaders, a string of early military victories, fighting a two front war, and unrest being higher within the Union. Texas eventually breaks away from the confederacy. Maybe Louisiana too. Deseret forms out west. California leaves the Union. Alaska breaks away from Russia on its own later on. Oregon, Washington, and Idaho form a independent nation out west after the federal government shows a lack of stability and control of the region. Native American nation forms somewhere maybe as a puppet.
