Gene,
You are absolutely right, Joe Rosenthal's Pulitzer prize photo of the second flag raising on Mount Suribachi is one of the best known photos in the world.

While this photo is one of the great ones, it (IMO) is normally used for Memorial Day, Veterans Day and other occasions having to do with the military.

The 4th of July being Independence Day, one would think of fireworks, flags, red white and blue and gala celebration, not one of the bloodiest battles of WWII.

Just my opinion and of course that and $1.50 buys a cup of coffee.