The issue of voting rights in the United States, specifically the enfranchisement and disenfranchisement of different groups, has been contested throughout United States history.
Eligibility to vote in the United States is established both through the federal constitution and by state law. Several constitutional amendments (the 15th, 19th, and 26th specifically) require that voting rights cannot be abridged on account of race, color, previous condition of servitude, sex, or age for those above 18; the constitution as originally written did not establish any such rights during 1787–1870. In the absence of a specific federal law or constitutional provision, each state is given considerable discretion to establish qualifications for suffrage and candidacy within its own respective jurisdiction; in addition, states and lower level jurisdictions establish election systems, such as at-large or single member district elections for county councils or school boards.
Beyond qualifications for suffrage, rules and regulations concerning voting (such as the poll tax) have been contested since the advent of Jim Crow laws and related provisions that indirectly disenfranchised racial minorities. Since the Voting Rights Act of 1965, the 24th Amendment to the Constitution, and related laws, voting rights have been legally considered an issue related to election systems. The Supreme Court ruled in 1964 that both houses of all state legislatures had to be based on election districts that were relatively equal in population size, under the "one man, one vote" principle. In 1972, the Court ruled that state legislatures had to redistrict every ten years based on census results; at that point, many had not redistricted for decades, often leading to a rural bias.