Journalists and staff were allowed back on to the grounds some time later but a partial lockdown of the northwest side of the building remained in place.
Video showed the intruder running across the White House lawn toward the president’s residence.
A U.S. Secret Service spokesman said the man had been apprehended but declined further comment.
Obama and his daughters had left the White House beforehand, departing on board the Marine One helicopter for Camp David, the presidential retreat in nearby Maryland.
Shortly thereafter, the intruder successfully got on to the grounds, and uniformed Secret Service personnel ordered the press corps and members of the White House staff to evacuate. (Reuters)