A piece of American history that I find fascinating is the prehistoric "highway" The Natchez Trace. It was an established route for native Americans and then was utilized by the Ohio river valley settlers. They would build flatboats to load their produce, furs/skins, and other products made and float down to New Orleans where they broke up the boats, sold the lumber and returned home on foot on the Trace. It's on my bucket list to bicycle from Franklin, TN to at least Jackson, MS. on the Trace.An elaborate system of "highways" to our ancestors and the settlers of this great country. By contrast, more than half of Australia's interior has no significant waterways, and as a result, those areas are still sparsely populated today. Access to water and transportation were the barriers.