Simplify the following text for a Grade 7 native English-speaking person.
Original: James Madison , Jr. ( March 16 , 1751 â `` June 28 , 1836 ) was an American politician and political philosopher who served as the fourth President of the United States ( 1809 â `` 1817 ) and is considered one of the Founding Fathers of the United States .
Simplified: James Madison ( March 16 , 1751 â `` June 28 , 1836 ) was the fourth President of the United States .