Within one year of the ratification of this amendment, every citizen of the United States shall be the citizen of a State.
A simple majority vote in Congress and among the citizens of Washington, D.C. or any territory is sufficient to create a new state. The new design of the Senate ensures that even tiny states will not have disproportionately large representation in the Senate.
Other options are possible. D.C. could be incorporated into Maryland. If Congress or a majority of the citizens of a territory vote against statehood, independence must ensue.
Independence, statehood, and incorporation into an existing state are all compliant with the proposition that all people are created equal.
It must be acknowledged that if tiny territories become states, they would be overrepresented in the House. Gerrymandering in the House is also a problem. Some advocate increasing the size of the House, and some advocate multi-member districts for the House. These are interrelated, complicated, lesser issues that we can later address under the simple majoritarian amendment power.