Complex sentence: At the time, McLean was already well known as the Marlboro Man, one of the more famous advertising campaigns in advertising history; ironically, he died of lung cancer (brought on by many years of smoking) in 1995.
Split into simpler sentences: At the time, McLean was already well known as the Marlboro Man, one of the more famous advertising campaigns in advertising history. Ironically, he would die of lung cancer (brought on by many years of smoking) in 1995.