It contains the following line:
Flies Old Glory, and she always will..."
"high on the hill Suribachi"
I'd assumed it was made a U.S. possession and remains one.
That's incorrect. It turns out that Iwo Jima was a U.S. possession for a long time, but was ceremoniously returned to Japan in mid-1968. But, then, "High on the hill Suribachi flies Old Glory, and she will for...twenty-three years" -- That just wouldn't have had as good a ring to it.