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.
Herbert Clark Hoover was an American engineer, businessman and politician who served as the 31st President of the United States from 1929 to 1933 during the Great Depression. A Republican, as Secretary of Commerce in the 1920s he introduced Progressive Era themes of efficiency in the business community and provided government support for standardization, efficiency and international trade. As president from 1929 to 1933, his ambitious programs were overwhelmed by the Great Depression, which seem