BOSTON — The U.S. Navy is naming a ship after Robert F. Kennedy.

Navy Secretary Ray Mabus announced the name Tuesday at the John F. Kennedy Presidential Library in Boston. Members of the Kennedy family, including his widow, Ethel Kennedy, attended.

Massachusetts Congressman Joe Kennedy, his grandson, said they’re “deeply grateful” for the honor.

The Robert F. Kennedy’s job will be to restock and refuel ships already at sea. Construction is expected to begin in 2021. Ethel Kennedy is the honorary sponsor and daughter Kathleen Kennedy Townsend is the sponsor, who will christen the vessel.

Ships in the class are being named in honor of civil and human rights heroes. Mabus said the class would be incomplete without Kennedy’s name.

Kennedy served as U.S. attorney general from 1961 to 1964 and as a U.S. senator from New York from 1965 to 1968. He was an advocate for the poor and for racial minorities. He was assassinated in 1968 during his campaign for Democratic presidential nominee.

“He said to those forgotten, ‘Your country sees you. Your country counts you. Your country needs you.’ This class of ships tells that story,” said Joe Kennedy.

“They are working ships, steady, sturdy vessels on which all other operations will depend, built by hardworking American hands, the great backbone of a force that projects peace and stability to every corner of our planet, and a fitting tribute to the names they proudly bear,” he said.

Mabus chooses ship names to help connect people with the Navy and Marine Corps. He spoke of how Kennedy inspired him and others to see politics and public service as a “noble profession, an opportunity to make the future bright for everyone.”

“It’s a legacy worth preserving by means of the Navy’s highest honor, having a ship bear his name and assigning that ship sponsors that personify his values,” Mabus said.