Mabus, a former governor of Mississippi, where Evers lived and died, announced the honor Friday at Jackson State University, The Jackson Clarion-Ledger reported. The vessel, a supply ship in the 700-foot Lewis and Clark class, is to be built at General Dynamics NASSCO in San Diego.
"The memory of Medgar Evers and what he did will be carried around the world," Mabus said.
Evers was 37 when he was gunned down outside his home in Mound Bayou in 1963. He served in the Army during World War II, graduated from Alcorn State University and worked for a black-owned insurance company while becoming a leader in the civil rights movement. At the time of his death, he was Mississippi field secretary for the National Association for the Advancement of Colored People.
Byron De La Beckwith was convicted in 1994 of Evers' murder.
Myrlie Evers-Williams said the announcement caught her by surprise, although Mabus promised her almost 20 years ago he would honor her husband.
"It's perhaps the best secret that has been kept from me," she said.