They descended from unmarked white school buses, many of them disoriented from hourslong journeys across the country, into a barrage of screams.

“Pick your heads up!” yelled a drill instructor. “Scream, ‘Aye, Ma’am!’ No! Scream louder than that!”

The women had come from places like Louisville, Ky., and Columbus, Ohio, in street clothes and sneakers, which they would soon shed for military fatigues. For the next 11 weeks , they would speak only in the third person, calling themselves “this recruit” instead of “I” to absolve all individuality.

They are recruits to Marine Corps Recruit Depot Parris Island, S.C. — the only place in the country where women become enlisted Marines.