https://www.youtube.com/watch?v=JUHnL6R39VM&t=7s
I read somewhere that the Federals were actually scared when they saw a graying middle-aged man charging at them with his hat through his sword. They couldn't believe that an old man would be willing (or physically capable enough) to do that.
Sadly, Armistead didn't live to see the end of the battle. But everyone remembers him as the highest ranking officer to reach "the high water mark".