Fifty-One States?

Puerto Ricans voted Tuesday on an important issue of their own: whether to join the United States, go independent, or establish a sovereign free association.

Statehood won, but not without division--the pro-statehood governor was kicked out.

His replacement is planning a constitutional assembly in 2014.

I didn't know how a state joins the union--good thing there's an Internet!

Update: Excellent breakdown of the situation at Daily Kos: Puerto Rico--Statehood and Status.