Could an independence referendum happen in the United States? What would have to happen before that, when would it most likely happen, and what state would it be the most plausible to have it happen in?
What he said. Alternatively, other previously held American Overseas Territories seem like plausible options- for instance, planning and holding an independence referendum for The Philippines after the Filipino–American War, rather the unilateral commitment by the US government to eventually grant independence to the Philippines.