James Clapper served as the fourth United States Director of National Intelligence--the United States' top intelligence officer and President Obama's senior intelligence advisor--from 2010 until 2017. Beginning his career as an enlisted Marine Corps reservist in 1961, Clapper eventually became a three-star Air Force lieutenant general and director of the Defense Intelligence Agency, retiring from uniformed service in 1995. In 2001 he returned to service, becoming the first civilian director of the National Imaging and Mapping Agency just three days after 9/11. In 2007 he was appointed the Pentagon's top intelligence official, serving as an appointee for both the Bush and Obama administrations before President Obama appointed him as DNI.