May 8, 1999: The first female cadet graduates from The Citadel.

A teeny bit of background from the LA Times:

CHARLESTON, S.C. — The Citadel graduated its first female cadet Saturday, ending a male-only tradition at the military school that stretched more than 150 years before ending as a result of a federal court fight.

Nancy Ruth Mace, a magna cum laude graduate in business administration, received her degree from her father, Emory Mace, the school's commandant of cadets.

In a news conference after the ceremony, she told reporters she does not regard herself "as a pioneer" in ending single-gender education at The Citadel.

While I know there must be other applicable books, the first one that comes to mind is Marie Lu's Legend, since the heroine, June, is also famous for a military first: she's the first one in history to have earned a perfect score on the test that decides the future of every citizen: 

Cinematic action, romance, politics, extremely sketchy medical experiments, some possible Soylent Green-ish doings (<--that one is extremely unlikely, but sicko that I am, I can't help but hope for it), codes, cage fights, and a couple of seriously shocking-ass moments... Legend is fun stuff. I don't know if I totally buy the speed at which June and Day trust each other (especially after [REDACTED]) and for people that should be mega-guarded and focused on life-and-death stuff, they sure do think about the smoochies a whole lot, but that certainly didn't stop me from reading it in one sitting.

Man, I NEED to read Prodigy.