There was no African American champion at the 1956 French Open.
Martina Hingis won the Australian Open title in 1997 at age 16 years and 3 months.
In 1989, Michael Chang of the USA won the French grand slam title at 17 yrs, 3 months. He also holds the record for the youngest winner of any grand-slam tennis tournament.
I believe it was Michael Chang, 17 years old, French Open, 1989.
Serena Williams won the 2013 women's singles French Open title.
Rafael Nadal won the 2013 Roland Garros French Open title.
In 2007, Rafael Nadal took the French Open title.
Rafael Nadal has won the most number of singles title at French Open.