The Constitution’s "Admissions Clause" is pretty vague on what’s necessary to become a state. Article IV, Section 3, Clause I says "new States may be admitted by the Congress into this Union."
The House Oversight Committee held a hearing on potential statehood for Washington, D.C., this week. But Rep. Jody Hice, R-Ga., had some new ideas about requirements for the District of Columbia to qualify as the 51st state.-- More...