The honor comes several months after President Obama last year visited the Tehachapi Mountains hamlet of Keene to dedicate the Cesar E. Chavez National Monument.
In 2011, Interior Secretary Ken Salazar added the headquarters of the United Farm Workers and Chavez's residence from 1971 to his death in 1993 to the National Register of Historic Places. The Navy christened the newest cargo-ammunition ship for Chavez, who served in the Navy during World War II.
Obama's visit came as the struggling United Farm Workers celebrates its 50th anniversary. By the time Chavez died in 1993, the labor leader and his union had been written off by detractors who called them irrelevant in contemporary labor, cultural and political issues.