Before statehood was granted, the land was occupied by settlers who had squatters’ rights. Why would statehood be necessary if the US already had jurisdiction and ownership???
http://usgovinfo.about.com/od/uscongress/a/statehoodproc.htm
The Typical Process
Historically, Congress has applied the following general procedure when granting territories statehood:
The territory holds a referendum vote to determine the people’s desire for or against statehood.
Should a majority vote to seek statehood, the territory petitions the U.S. Congress for statehood.
The territory, if it has not already done so, is required to adopt a form of government and constitution that are in compliance with the U.S. Constitution.
The U.S. Congress - both House and Senate - pass, by a simple majority vote, a joint resolution accepting the territory as a state.