Simplify the following text for a Grade 7 native English-speaking person.
Original: George Stoneman , Jr. ( August 8 , 1822 â `` September 5 , 1894 ) was a career United States Army officer , a Union cavalry general in the American Civil War , and the 15th Governor of California between 1883 and 1887 .
Simplified: George Stoneman , Jr. ( August 22 , 1822 â `` September 5 , 1894 ) was a career U.S. Army officer , a Union cavalry general in the American Civil War , and the Governor of California between 1883 and 1887 .