Simplify the following text for a Grade 7 native English-speaking person.
Original: In 1910 , Colonel Charles W. Harris , head of the Arizona National Guard , designed a flag for the Arizona Rifle Team when they attended the National Matches at Camp Perry .
Simplified: In 1910 , Colonel Charles W. Harris , head of the Arizona National Guard , made a flag for the Arizona Rifle Team when they attend the National Matches at Camp Perry .