The White House displayed a happy 100th birthday sign for former President Jimmy Carter on the North Lawn on Tuesday. It is the first time an American president has lived a full century and marks a milestone in a life that took the son of a Depression-era farmer to the White House and across the world as an advocate for democracy. The Democrat served as president from 1977 to 1981 and then worked for more than four decades leading The Carter Center, a non-governmental organization he and wife Rosalynn co-founded in 1982.