The highway interchange at Interstate 20 and Mississippi Highway 15 will be named "Medgar Evers Memorial Interchange.'' The designation becomes official on July 1.
Evers, a Newton County native, was Mississippi NAACP field secretary from 1954 until he was assassinated the night of June 12, 1963, in the driveway of his Jackson home.
Evers was known for promoting black voter registration at a time when poll taxes, literacy tests and violence tried to prevent it.
As a World War II veteran who had fought in France, Evers tried to register to vote in 1946 at the Newton County Courthouse in Decatur, only to be turned away by an angry white mob.
Last year, on the 40th anniversary of his slaying, blacks and whites gathered in Decatur to celebrate Evers' legacy.
Segregationist Byron De La Beckwith was tried twice in 1964 for Evers' slaying, but all-white juries deadlocked and Beckwith walked free. Beckwith was eventually convicted of murder in 1994 and died in custody on Jan. 21, 2001.