Not too quibble too much, but US Civil War soldiers were marching all over the eastern United States, not just for parades and pageants. They went through rough terrain, with no guarantee of supplies, and many soldiers ended up barefoot when their shoes fell apart. And many times they had to keep it up for days on end in order to escape or catch up to an enemy.
Fair, but they also carried considerably less weight at 40-50lbs versus the 80lbs that a Roman legionnaire carried and the 100-120lbs troops deployed in Afghanistan could be carrying.
