Spelman College graduates got one last lesson in success Sunday from a woman who knows something about it.

Oprah Winfrey, who created a media and philanthropic empire, urged more than 550 graduates at the historically black college for women to strive for excellence and make service the focus of their lives. And she told them to remember the sacrifices of generations of ancestors whose blood and hard work paved the way for their accomplishments.

"Never forget that you did not do this by yourself," Winfrey told the graduates and their families at Spelman's 125th commencement ceremony. "You come here today trailing the breath of the ancestors and of the angels."

It was a banner day for two Atlanta historically black colleges. Earlier Sunday, more than 500 men graduated from Morehouse College.

At the Georgia International Convention Center, Winfrey cited three keys to success.

First, she urged graduates to know themselves and what they want. “My answer is, I am God’s child,” Winfrey said.

“You must have some kind of vision for your life, even if you don’t have a plan,” she said.

Winfrey also told graduates to find a way to serve and to always do the right thing.

“Do the right thing, even when other people think it may not be,” she said.

Winfrey parlayed an early career in local broadcasting into the highest-rated talk show in television history, “The Oprah Winfrey Show.” Later she founded her own studio and cable network.

Spelman honored her with an honorary doctorate in 1993 and on Sunday bestowed its Community Service Award upon her. Among other things, she created Oprah’s Angel Network, which has raised more than $80 million for charity projects around the world. And her Oprah Winfrey Foundation has awarded hundreds of grants to groups that support the education and empowerment of women, children and families.

Winfrey’s message resonated with Dymon Morgan, Spelman's senior class president.

“Absolutely loved it,” she said after the ceremony. “Really knowing yourself is so important.”

Hundreds of parents and friends cheered the graduates as, one by one, they received their diplomas. Among them was Cedric Sturdivant, who watched his daughter Quinyae earn a bachelor’s degree.

The music vocal performance major, who plans to move to New York this fall, said graduating is bittersweet. But for dad, it’s the fulfillment of a dream he’s nurtured since 1980.

“The first time I ever saw the campus, I thought, if I ever have a daughter, I want her to go to Spelman,” he said.