When the US (east coast) was first settled, it was largely by indentured servants and prisoners. The settling of the US west parallels the cossack settlements

When the US (east coast) was first settled, it was largely by indentured servants and prisoners. The settling of the US west parallels the cossack settlements - these guys were free to take land and paid few taxes, but were expected to defend themselves. Normally the goverments of Poland and Russia tried to reduce the cossacks to serfdom (which triggered wars like the great rebellion of Bohdan Khmelnytsky) or at the very least turn them into a warrior class that enforces the serfdom institution (like what happened with the Russian cossacks after the defeat of the big cossack-peasant uprisings there). I think the North of the US started colonizing the West late, when the North was already pretty urbanized, densely populated and industrial, which made the free-soil type settlement possible. The South of course was still fully agricultural, which insentivised a different type of settlement driven by soil erosion by inefficient slave-based agriculture.