With two months to go before American voters choose their president the Democrats are gathering for their national convention when Barack Obama will officially accept his party's nomination for a second term.
Win or lose in November he'll always be remembered as the nation's first black president.
The BBC's North America editor Mark Mardell considers the impact of his first term on black Americans and the office of the presidency.
To many African-Americans Obama is seen as the ultimate role model, proving that nothing is beyond their reach.
“There are children who are now the age of four, soon to be five, who will have known only a black man at the seat of power of this nation,” says American artist Kehinde Wiley.
But the black-white relationship has also been a big challenge for Obama. As the nation's first black president, he has borne the brunt of vitriolic political attacks, over his name, his background, his religion, and is often painted as alien and un-American.
Nevertheless, traditional election issues like the state of the economy could be his biggest challenge in November.
