Voter registration in the United States
All US states and territories, except North Dakota, require voter registration by eligible citizens before they can vote in federal, state and local elections. In North Dakota, cities in the state may register voters for city elections, and in other cases voters must provide identification and proof of entitlement to vote at the polling place before being permitted to vote.
Source: Wikipedia — Voter registration in the United States (CC BY-SA 4.0)