華盛頓特區建州運動gov. [March 14, 2021]. (原始内容存档于March 23, 2021). 美國第51州 加入美國聯邦(英语:Admission to the Union) 2016年華盛頓特區建州公投(英语:2016 Washington, D.C. statehood referendum) 波多黎各建州運動
阿拉巴馬領地of the western part of the Mississippi territory to form a constitution and state government, and for the admission of such state into the union, on