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.
Jim Powell. The Great Depression of the 1930s was by far the greatest economic calamity in U.S. history. In 1931, the year before Franklin Roosevelt was elected president, unemployment in the United States had soared to an unprecedented 16.3 percent. In human terms that meant that over eight million Americans who wanted jobs could not find them.