a free market with limited government regulation of business.
Explanation:
First of all, Lassez-Faire means something very close to "let things happen" in a way in which is declared that the government should business happen, without worries. This doctrine is conceived as an economic model in which the economy would self-regulate itself as well as businesses and the markets. In this model, the government only takes care of managing the rights of individuals. Therefore, the lassez-faire doctrine is a model of the free economy in which the government doesn't do anything to regulate it.
However, westward expansion provided the United States with vast natural resources and ports along the Atlantic, Pacific and Gulf coasts for expanding trade, key elements in creating the superpower America is today.