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.
So, the chart below gives the events and their ranges. The average age for periods in the U.S. is 12.16 for black girls and 12.88 for whites. By age 11, 28% of black girls and 13.5% of whites menstruate. By age 12, 62% of blacks, and 35% of whites. A girl's first menstruation is called menarche.