Reynolds v. Sims (1964)
Definition - What does Reynolds v. Sims (1964) mean?
The case of Reynolds v. Sims determined that state legislature districts had to be roughly equal in size. The court case was taken in Alabama but had an effect on all states.
Justipedia explains Reynolds v. Sims (1964)
The reason why the case was taken was due to the unfairness in representation that existed prior to that judgment, wherein larger constituencies would be able to receive more grant funding from the government and have more sway over votes on any local or state policy.