In 1992, Casey's father, the late Pennsylvania Gov. Robert P. Casey, was denied a prime-time slot to speak in opposition to abortion rights, which created a rift within the party.
"Barack Obama and I have an honest disagreement on the issue of abortion," Casey said. "But the fact that I'm speaking here tonight is testament to Barack's ability to show respect for the views of people who may disagree with him."
Before Pennsylvania's competitive Democratic primary, Casey endorsed Obama over Sen. Hillary Rodham Clinton, also an abortion-rights supporter, and campaigned with Obama.
"I'm honored to stand before you as Governor Bob Casey's son and a proud supporter of Barack Obama," Casey said at the start of the speech, which focused on Obama and the economy.