Shortly after commissioning, "New York" became flagship for the United States occupation of Veracruz in 1914. During World War I, she became flagship of Battleship Division 9, commanded by Rear Admiral Hugh Rodman. Sent to reinforce the British Grand Fleet in the North Sea, she conducted blockade and escort duties. She twice came into contact with German U-boats, and is believed to have accidentally sunk one. She returned to the United States at the end of the war, and began taking on patrol and training duties. "New York" was fitted with XAF RADAR in February 1938, including the first United States duplexer so a single antenna could both send and receive.