"In reaffirming the greatness of our nation, we understand that greatness is never a given. It must be earned," Obama said in his inaugural address.
The time has come, he said, "to reaffirm our enduring spirit; to choose our better history; to carry forward that precious gift, that noble idea, passed on from generation to generation: the God-given promise that all are equal, all are free, and all deserve a chance to pursue their full measure of happiness."
He recognized today's ancestors and fore-bearers and the sacrifices they made because "they saw America as greater than the sum of our individual ambitions."
There's plenty of work to be done, Obama said, whether it is to repair the economy, improve the education system and healthcare, or search for alternative energy.
"All this we can do," he said. "And all this we will do."