Olusegun Obasanjo is the only Nigerian President who had officially hosted three incumbent President of the United States of America. President Buhari has no such record
Jimmy Carter (March 31 — April 3, 1978),
Bill Clinton (August 26 — 28, 2000), and
George W. Bush (July 11 — 12, 2003).
In other words, every sitting American President visited Obasanjo while he was President/Head-of-State; the only Nigerian President to have achieved this feat. He, of course, visited the White House in return.
While President Muhammadu Buhari is amongst President who has not attended this feat, former President Olesegun Obasanjo is the only one who has achieved this in the whole African continent