Facebook's Mark Zuckerberg biggest US 2013 giver
Mark Zuckerberg and his wife, Priscilla Chan, were the most generous American philanthropists in 2013, with a donation of 18 million shares of Facebook stock, valued at more than $970 million, to a Silicon Valley nonprofit in December.


The Chronicle of Philanthropy reported Monday that Zuckerberg's donation was the largest charitable.gif" style="display:nonet on the public record in 2013 and put the young couple at the top of the magazine's annual list of 50 most generous Americans in 2013. (AP)