<P> Voter registration in the United States takes place at the county level, and is a prerequisite to voting at federal, state and local elections . The only exception is North Dakota, although North Dakota law allows cities to register voters for city elections . </P> <P> A 2012 study by The Pew Charitable Trusts estimates that 24% of the voting - eligible population in the United States are not registered to vote, a percentage that represents "at least 51 million eligible U.S. citizens ." Numerous states had a history of creating barriers to voter registration through a variety of fees, literacy or comprehension tests, and record - keeping requirements that in practice discriminated against racial or ethnic minorities, language minorities, and other groups . The Voting Rights Act of 1965 forbade such abuses and authorized federal oversight in jurisdictions of historic under - representation of certain groups . States continue to develop new practices that may discriminate against certain populations . By August 2016, federal rulings in five cases have overturned all or parts of voter registration or voter ID laws in Ohio, Texas, North Carolina, Wisconsin, and North Dakota that were found to place undue burden on minorities and other groups among voters . The states are required to offer alternatives for the November 2016 elections; many of these cases are expected to reach the US Supreme Court for additional hearings . </P> <P> While voters traditionally had to register at government offices by a certain period before an election, in the mid-1990s, the federal government made efforts to simplify registration procedures to improve access and increase turnout . The National Voter Registration Act of 1993 (the "Motor Voter" law) required state governments to either provide uniform opt - in registration services through drivers' license registration centers, disability centers, schools, libraries, and mail - in registration, or to allow voter registration on Election Day, where voters can register at polling places immediately prior to voting . From January 1, 2016, Oregon was the first state to adopt a fully automatic (opt - out) voter registration system as part of the process of issuing driver licenses and ID cards . By April 2016 three more states - California, West Virginia, and Vermont - followed suit, and in May 2016 Connecticut implemented it administratively rather than by legislation, bringing the number of states with automatic voter registration to five . Alaskan voters approved Measure 1 during the November 8, 2016 general election, allowing residents the ability to register to vote when applying annually for the state's Permanent Dividend Fund . Voter approval of Measure 1 made Alaska the first state to implement automatic (opt - in) voter registration via ballot initiative and the sixth state to implement automatic registration by any means including passing legislation . Several more states have drafted legislation proposing automatic registration . </P> <P> Political parties and other organizations sometimes hold voter registration drives, organized efforts to register groups of new voters . </P>

A district in which all voters report to the same polling place is called a