Complex sentence: As of February 1990, he and Mary Jo with whom he had been married for 15 years had 5 children ranging in age from 1 to 7 with the oldest two adopted.
Split into simpler sentences: As of February 1990, he and Mary Jo had been married for 15 years. At that time, they had 5 children ranging in age from 1 to 7 with the oldest two adopted.