For example, the average age of the onset of menstrual periods in girls was 15 in 1900. By the 1990s, this average had dropped to 12 and a half years of age.uberty facts. 1  Puberty is the period of sexual maturation and achievement of fertility. 2  The time when puberty begins varies greatly among individuals; however, puberty usually occurs in girls between the ages of 10 and 14 and between the ages of 12 and 16 in boys.
Herbert Hoover was the president of the U.S. when the great depression began in 1929.
Updated May 29, 2016. Franklin D. Roosevelt, the 32nd President of the United States, led the country both during the Great Depression and World War II. He was charismatic and innovative at a time when the United States needed exactly that kind of leadership.