What aspect of the american economy improved in the 1820s?

Between 1790 and 1820, the population of the United States more than doubled to nearly 10 million people. Remarkably, this growth was almost entirely the result of reproduction, as the immigration rate during that period had slowed to a trickle. Fewer than 250,000 immigrants entered the United States due to doubts about the viability of the new republic and travel restrictions in Europe during the French Revolution and Napoleonic Wars.