Statehood produced legal continuity, not breakage, across the West

Evidence

Once a territory became a state, it had complete power to make and unmake its own laws, and to do exactly as it (or its electorate) liked. There was, in fact, a great deal of continuity, just as there was in the thirteen original states after they broke away from England. The common law survived everywhere. Governor Ford thought that western legislatures passed too many laws, that they overturned too much too soon: “A session of the legislature was like a great fire in the boundless prairies of the State; it consumed everything. And again, it was like the genial breath of spring, making all things new.” But this was almost certainly a gross exaggeration. The statute books of the northwest states were, by modern standards, skimpy and undernourished. New states were faithful, on the whole, to what they inherited. Ohio, even after it became a state, kept the statutes left over from its days as part of the Northwest Territory. These territorial laws were handed on to Indiana Territory (1800); Indiana passed them to Michigan and Illinois territories (1809); Michigan Territory was the source of the earliest laws of Wisconsin Territory (1836), which in turn delivered them to Iowa (1838) and Minnesota (1849). In the Southwest, the line went from Louisiana to Missouri Territory (1812), from there to Arkansas (1819), and from Mississippi to Alabama (1817). — Lawrence M. Friedman, A History of American Law, 918