(AP) - President Barack Obama on Thursday traced his historic rise to power to the vigor and valor of black civil rights leaders, telling the NAACP that their sacrifice "began the journey that has led me here." The nation's first black president bluntly warned, though, that racial barriers persist.

"Make no mistake: The pain of discrimination is still felt in America," the president said in honoring the organization's 100th convention.

Rousing up his audience, Obama offered his most direct speech on race since winning the White House, a mix of personal reflection and policy promotion. He worked on it for about two weeks and revised it until shortly before he spoke, his aides said, underscoring the importance of his message and his audience.

Implicit in his appearance: He is seeking the backing of the powerful NAACP and its members for his ambitious domestic agenda.