*Alien and Sedition acts of 1799 are not resolved and states push to ignore or 'nullify' enforcement of laws they do not agree with
*Louisiana Purchase is never ratified but illegal settler colonies emerge roughly along OTL lines
*Andrew Jackson loses his 1806 duel and dies
*By the end of War of 1812 the Union is broken as the Confederacy of New England secedes with a capitol at Hartford. Vermont, Massachusetts, Rhode Island, New Hampshire, Connecticut, and the future states of Maine and New Ireland leave as Britain reclaims West Florida and much of the southern Mississippi basin following their victory at the Battle of New Orleans.
*Treaty of Ghent gives US lands north of the Arkansas Rivers and Yazoo river junction with the Mississippi to the US, Britain retains control of the lands elsewhere east to the Mobile River.
*Adams and Onis barely manage to get the Spanish out of peninsular Florida but remain unable to extirpate its native populations
*John C Calhoun cites trade issues and pervasive inability of Washington to enforce its own edicts. South Carolina along with Georgia, Tennessee, Kentucky, North Carolina, Maryland, Delaware, Missouri, Southern Illinois, and Virginia secede as do truncated Alabama & Mississippi (northern halves of the states only) along with the Florida Territory. This new Federation of North American States based our if Charleston seeks to industrialize as rapidly as possible.
*In 1836 Texas secedes and establishes a Republic recognized by UK in 1841. Confederacy begins colonization efforts in Africa and Asia as US and FNAS colonize the West, including an FNAS mission successfully establishing a colony at New Richmond (Portland OR of OTL).
*Mormon church successfully establishes an independent nation in Deseret in 1847 with recognition coming from 1850
*California Gold rush prompts massive immigration and self-determination followed by independence in 1849 inclusive of OTL Nevada
*CaliMexican war results in defeat for Mexico after guerilla warfare and aid from Texas, France, England, Deseret, and the FNAS which has colonized Kansas and Oklahoma. Deseret takes Colorado and Arizona north of the Colorado River while securing (and planning to colonize) much of Wyoming and southern Idaho, Texas takes New Mexico and the remainder of Arizona along with a sliver of land on the Gulf of California. California gets Baja California, Republic of the Rio Grande gets independence, and the FNAS claims Oregon from California up to the Columbia River; north of that is British Columbia and Victoria. Mexico becomes a monarchy under Maximilian but without US help the rebels flounder.
*Over the next 40 years, US colonization efforts claim Nebraska, the Dakotas, and west to the Rockies while FNAS efforts claim Hawaii. Texas and California form a defensive pact while the US drifts apart with Chicago as capitol of the new American Alliance. Ohio, New York, New Jersey, Pennsylvania, and Michigan remain in the United States governed from Philadelphia while the rest go their own way. Yucatan guerilla fighters earn independence in 1875 as Canada gains official Dominion status in 1887; as the 20th century dawns, the continent looks akin to a carved turkey on a European table.