In Wesberry v. Sanders the Supreme Court of the United States rules that congressional districts have to be approximately equal in population.
Wesberry v. Sanders, 376 U.S. 1 (1964), was a landmark U.S. Supreme Court case in which the Court ruled that districts in the United States House of Representatives must be approximately equal in population. Along with Baker v. Carr (1962) and Reynolds v. Sims (1964), it was part of a series of Warren Court cases that applied the principle of "one person, one vote" to U.S. legislative bodies.
Article One of the United States Constitution requires members of the U.S. House of Representatives to be apportioned by population among the states, but it does not specify exactly how the representatives from each state should be elected. The case arose from a challenge to the unequal population of congressional districts in the state of Georgia.
In his majority opinion, which was joined by five other justices, Associate Justice Hugo Black held that Article One required that "as nearly as practicable one man's vote in a congressional election is to be worth as much as another's." The decision had a major impact on representation in the House, as many states had districts of unequal population, often to the detriment of urban voters. The United States Senate was unaffected by the decision since the Constitution explicitly grants each state two senators.