President Barack Obama has called on all Americans to throw themselves "into the work of citizenship".
In the final radio and internet address of his presidency, Mr Obama said the country's success depends on everyone participating - not just at election time but during the course of one's lifetime.
He said that every American holds the title of "citizen" despite their many differences, and added that "citizen" is a title he is looking forward to reclaiming after eight years as president.
Mr Obama said being president has been his life's honour and he learned every day from the ordinary people he had conversations with, which made him both a better president and a better man.