"One-hundred-fifty years ago, Abraham Lincoln said, 'The world will little note, nor long remember what we say here,'" Jewell said. "He was wrong. Just as the battle that raged on these fields stands at the vortex of American history, Lincoln's words stand at the vortex of our national consciousness."
Jewell said Lincoln's words remain as a reminder of "the sacrifice of so many for freedom," and the nation's "long journey, still ongoing, to fulfill the fundamental proposition that indeed all men and women are created equal and deserve the full benefit of this freedom that has been purchased at such great price."
"They tell us what it means to be an American," she said. "They call us to unfinished work, not just to win a war, but to continue to perfect our nation and a government that is truly "of the people, by the people, for the people."
Pennsylvania Gov. Tom Corbett, the state's two U.S. senators -- Bob Casey and Pat Toomey -- and U.S. Supreme Court Justice Antonin Scalia attended the ceremony. Scalia presided over the swearing in of more than a dozen new U.S. citizens, Fox News reported.
The White House announced last month President Barack Obama would not attend the ceremony.
White House senior adviser Dan Pfeiffer, responding to a Twitter inquiry, said the president was unable to attend due to scheduling issues related to implementation of the Affordable Care Act.
"Oh, I don't know, there's this whole website thing that someone suggested might destroy the [Democratic] Party," Pfeiffer tweeted.
White House press secretary Jay Carney said Monday "all Americans across the country will have the opportunity to think about those words and that address."