The average age of listees in Who’s Who in America is in the mid-50s, but there are some very young listees as well. The youngest listees are child actresses Shirley Temple and Margaret O’Brien.

Shirley Temple, who had already acted in more than 15 movies, makes her debut in the 1936-1937 edition of Who’s Who in America with a 19-line biography. Ms. Temple was born on April 23, 1928, which makes her 9 years old at the time of publication. However, all-time honors for youth go to Margaret O’Brien, who, after appearing in 10 movies, makes her debut in Who’s Who in America at age 8, in the 1946-1947 edition, with a nine-line biography.