Howard is the first African-American woman to achieve three star rank in the U.S. Armed Forces. She is the first African-American woman to command a U.S. Navy ship. In 2006, she was selected for the rank of Rear Admiral lower half, making her the first admiral selected from the United States Naval Academy class of 1982 and the first woman graduate of the United States Naval Academy selected for Admiral.
Howard took command of USS Rushmore (LSD-47) on March 12, 1999, becoming the first African-American woman to command a ship in the U.S. Navy. Howard commanded Amphibious Squadron 7 from May 2004 to September 2005. Deploying with Expeditionary Strike Group (ESG) 5, operations included tsunami relief efforts in Indonesia and maritime security operations in the North Persian Gulf.
Howard's shore assignments include: Course Coordinator/Instructor for the Steam Engineering Officer of the Watch (EOOW) course; Action Officer and Navy’s liaison to the Defense Advisory Committee on Women in the Military Services (DACOWITS) in the Bureau of Personnel; Action Officer J-3, Global Operations, Readiness on the Joint Staff from 2001–2003; Executive Assistant to the Joint Staff Director of Operations from February 2003 to February 2004; and Deputy Director N3 on the OPNAV Staff from December 2005 to July 2006.
Howard was the Deputy Director, Expeditionary Warfare Division, OPNAV staff from July 2006 to December 2006, and senior military assistant to the secretary of the Navy January 2007-January 2009.She served as chief of staff to the director for Strategic Plans and Policy, J-5, Joint Staff from August 2010 until July 2012.
Howard assumed command of Expeditionary Strike Group (ESG) 2 and Combined Task Force (CTF) 151 aboard the amphibious assault ship USS Boxer (LHD-4) in April 2009. The USS Boxer was the flagship for CTF 151, a multinational task force established to conduct counter-piracy operations in the Indian Ocean.
Howard was promoted to Rear Admiral (lower half), effective September 1, 2007 and to Rear Admiral, effective August 1, 2010. She was promoted to Vice Admiral on August 24, 2012.