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.
In the 1990âs, when the U.S. study was conducted, the average age of an American girlsâ first menstruation is similar to what it was a generation ago: 12.1 years old for African Americans and 12.8 for white girls. The average age for beginning menarche dropped 3.5 months from 1991 to 2006 for the Danish girls.