The executive branch is composed of the President, Vice President and Cabinet members. President The president is the head of state, head of the U.S. government and the commander-in-chief of the U.S. military.
Menarche. The average age of menarche, or first menstruation, in the United States is 12.88 years for Caucasian girls and 12.16 years for African American girls. A popular misconception is that menarche marks the beginning of puberty; in reality, menarche occurs later in puberty.
According to Tanner, the average age of menarche dropped from about 17 to 12.8 during the period 1830-1962. The rate of decline was 4 months per decade. Tanner has also noticed a decline in the age of initiation of the growth spurt. The trend seems to have stopped, with the age of menarche leveling off at 12.6.