Simplify the following text for a Grade 6 native English-speaking person.
Original: James Earl `` Jimmy '' Carter , Jr. ( born October 1 , 1924 ) served as the 39th President of the United States ( 1977 â `` 1981 ) and was the recipient of the 2002 Nobel Peace Prize , the only U.S. President to have received the Prize after leaving office .
Simplified: James Earl `` Jimmy '' Carter , Jr. ( born October 1 , 1924 ) was the 39th President of the United States from 1977 to 1981 .