Not wearing, but we do put the American flag up on Independence Day! A lot of Americans hereabouts due to a couple sizable military bases, so it's not so uncommon down here.
Inkaneer, I agree the feeling at Gettysburg is hard to describe, especially if you know a little about the battle before you go there. There was another event that happened on July 4, 1863, Vicksburg Mississippi surrendered to US Grant that day, I understand that Vicksburg did not celebrate Independence Day again until 1943.