Complex sentence: Mark Mitchell Campbell (December 31,1897--June 21,1963) was a barnstormer, movie stunt man, Lockheed executive from 1934-1960, and co-founder of the Silver Wings Fraternity in California.
Split into simpler sentences: Mark Mitchell Campbell (December 31,1897--June 21,1963) was a barnstormer, movie stunt man, Lockheed executive from 1934 to 1960. He was the co-founder of the Silver Wings Fraternity in California.