Simplify the following text for a Grade 8 native English-speaking person.
Original: William Henry Harrison ( February 9 , 1773 - April 4 , 1841 ) was the ninth President of the United States ( 1841 ) , an American military officer and politician , and the first president to die in office .
Simplified: William Henry Harrison ( born February 9 , 1773 , died April 4 , 1841 ) was the 9th President of the United States .