Here's what I found...I'm fixing to be on my way out the door,so didn't have time to search that site in more detail,but here's part of it...I know it doesn't answer you question,just wanted to point out that,according to this site,he has more than just the 1 son...
http://sun.menloschool.org/~sportman/ethnic/individual/powell/index.html
Although there was much speculation that Powell would obtain the presidential bid in 1996, he declined any such offer. Powell's decision not to run shocked many, as most Americans believed Powell had a very promising shot at winning and becoming the first black President of the United States. Concern for his wife, three children, and two grandchildren kept him wary of running. His wife received racist hate mail concerning the possibility of Powell running, and Powell maintained his stance that respect and agreement among family members were of the most importance. "General Powell's decision not to run for president was a mutual decision by him and Alma, his wife of 33 years," People reported. Powell knew Alma was not comfortable with the thought of presidency, and so he declined the bid. His stress on family values clearly stems from his own parents' teachings while he was growing up.