"It's a happy feeling," he said, adding school had taught him "to not wait, to keep on working hard."
James Thornton, a county school board member, told the students they are "special" because they persevered and overcame their personal obstacles.
He encouraged them to help the less fortunate, give back to their community, visit the elderly and give back in other ways to the world around them.
"You have an obligation as you move beyond the walls of this institution," he said, quoting Morehouse College's Benjamin Mays that "the tragedy of life does not lie in not reaching your goals; the tragedy lies in not having any goals to reach."
Carol Frontera, of the Albert P. Close Foundation, gave the class some advice she tells her children when they leave for school: "Make good choices and do great things."