Hillary Clinton told graduates at Wilberforce University "journeys that led to the abolition of slavery still call us to finish the march to justice."The Associated Press reports that Clinton, who spoke at the historically black college's graduation ceremony Saturday, urged graduates to remain optimistic about their ability to fight injustice and change society for the better.

"That's what elections are for," Clinton said. "Don't let anyone wear you down to the point where you believe it is not worth trying to change your society any longer."

The AP reports a crowd of about 4,000 listened to the Democratic presidential candidate deliver the commencement address for about 225 graduates of Wilberforce University, a school of about 1,050 students about 15 miles east of Dayton that traces its roots back to 1856.

Clinton, a New York Democrat, told the crowd that if they turn a blind eye to injustices levied against women, minorities and the weak or vulnerable "we let it linger in the atmosphere."

Clinton was also set to appear Saturday with Cleveland leaders, including Democratic U.S. Rep. Stephanie Tubbs Jones, at a high school. Clinton is scheduled to return to Ohio in just a few days as the keynote speaker for the annual Ohio Democratic Party dinner in Columbus on May 12.