The purchase of Louisiana was perhaps the constitutional turning point in the history of the Republic, inasmuch as it afforded both a new area for national legislation and the occasion of the downfall of the policy of strict construction. But the purchase of Louisiana was called out by frontier needs and demands. As frontier States accrued to the Union the national power grew. In a speech on the dedication of the Calhoun monument Mr. Lamar explained: "In 1789 the States were the creators of the Federal Government; in 1861 the Federal Government was the creator of a large majority of the States."

frederick jackson turner, the significance of the frontier in american history, ch. 1