The United States has an all volunteer military. Although the United States requires all men to register with the draft when they turn 18 the draft is not currently being used to populate the armed forces. The answer to your question is: They volunteered.
I don't know but there's a military base in Guam
You are mixing services. Rangers are a part of the US Army. US Marines are a separate military unit.
Men that were here in the US. Only part of the US male population was in the military and away from the US.
During the Vietnam War, roughly about 2 million men world wide; women were part of the WACs (Women's Army Corps). The term(s) "How many men in the US Army" cannot be applied today (21st century). The WACs were disbanded in 1975.
and what year they i become a part of the us
You must name a time period. Prior to 1975 (the Vietnam era) the US Military was 100% men and 100% military. During that time frame US military women in all branches were considered AUXILIARIES and belonged to the WACs, WAVES, and WAFs. Women were not considered part of the US fighting strength. EDIT: Removed offensive material from answer.
Yes, an individual must be a current US Citizen to become an Officer in the US Military.
the Chinese because they have men
Yes, the Air Force is a part of a branch in the Military.
it became part of the us in 1832
In the US they register for the military draft.
money, and a strong military