(CNN) -

The U.S. Navy has promoted Vice Adm. Michelle Howard to admiral, making her the first female four-star officer in the Navy's 236-year-history, the White House said Tuesday.

Howard, who was the first African-American woman to command a Navy ship, will become vice chief of naval operations, according to her online Navy biography.

"Her historic career is taking a next step today," White House spokesman Josh Earnest said.

Howard's promotion comes nearly six years after Army Gen. Ann E. Dunwoody became the U.S. military's first female four-star officer.

Howard, a 1982 graduate of the Naval Academy, made history when she commanded the amphibious dock landing ship Rushmore in 1999, Earnest said.