He may be the world's foremost mixed-race leader, but when it came to the official government head count, President Barack Obama gave only one answer to the question about his ethnic background: African-American.

The White House confirmed on Friday that Obama did not check multiple boxes on his U.S. Census form, or choose the option that allows him to elaborate on his racial heritage. He ticked the box that says "Black, African Am., or Negro."

Obama filled out the form on Monday, supplying information for himself, first lady Michelle Obama and their daughters Malia and Sasha, as well as for Mrs. Obama's mother, Marian Robinson, who lives with the family in the White House.

For Obama, whose mother Ann Dunham, a white woman from Kansas, married his father, the Kenyan native Barack Obama Sr., the question of his racial identity has been a lifelong struggle. His first memoir, "Dreams From My Father," is an account of a difficult journey of discovery.