What is popular sovereignty? States choose (vote) whether to have slavery or not. States choose (vote) whether to have slavery or not. The Congress and Federal government decide on whether states will have slavery or not. The Congress and Federal government decide on whether states will have slavery or not. Outlawed slavery in the North after the American Revolution. Outlawed slavery in the North after the American Revolution. Allowed the South to have as many slaves as they wanted in any state they chose to go to. Allowed the South to have as many slaves as they wanted in any state they chose to go to. Stated that slavery may not exist in any state below the 36º 30º parallel.