"...schoolma'ams
make big bad boys remain after school; lads with ladders
steal lightly over lawns where Juliet waits in her trellissed
window with her telescope packed; young couples out
for a walk come home married; old chaps put on white
spats and promenade near the Normal School; even
married men, grown unwontedly tender and sentimental,
whack their spouses on the back and growl: "How goes
it, old girl:"

A famous Massachusetts educator, Horace Mann was able to
persuade the Legislature to establsh schools to train teachers. I'm not sure where the name "Normal" came from,
but I suspect it was French. Now the ones in MA are State
Universities.

I wonder if O.Henry got kept after school for private education about the facts of life.