The award is an acknowledgement of Paul's vast contributions to American culture. It will be given to him by President Obama at a ceremony in Washington, D.C. this December.
Side-note: First the Gershwin Prize and now this? I wonder if the man-crush that Macca has on Obama will eventually be reciprocated in full as the two see each other more and more. (That is, if it isn't already.) Or is it the case that Obama has too much of an imperial comportment for man-crushes?
Excerpt from this NME article:
Speaking about the annual award, McCartney said: "President Kennedy was such an icon for us in the '60s and his presidency was so inspiring for so many people that it is a great pleasure for this kid from Liverpool to receive this honour."
McCartney follows in the footsteps of the likes of Robert De Niro, Brian Wilson, Steven Spielberg and Bob Dylan in receiving the award.