Who is Henry Shreve, and what does he do?

Henry Shreve is an inventor who brings the Mississippi steamboat to the river. He is appointed Corps Superintendent of Western Improvements and is responsible for keeping the Mississippi River clear of debris so it can be navigable. Shreve invents multihulled snagboats to pull large trees, called snags, from the river. He also dredges dirt from one location, which inadvertently increases the flow of water from the Mississippi to the Atchafalaya.