What were economic changes from 1812 to the war with Mexico for the United States?

The War of 1812 had a stimulus impact on manufacturing in the United States. In addition, in the aftermath of that war, the export of cotton caused the economy of the south to surge. A protective tariff to support the new industrial base was applied and, between that and land sales, the federal government found itself well-financed.
At the same time, the so-called "market revolution," which marked a shift from an agrarian economy toward one founded on wage labor, had a significant impact on the nation's economic make-up. Meanwhile, infrastructure improvements like the Cumberland Road and the Erie Canal, the expansion of the railroad, and the arrival of the steamboat meant there was greater inter-state commerce.
While the United States experienced episodic disruptions during this time period (such as the Panic of 1837), they were, overall, not significant enough to impact the country's rapid economic growth during the era between the War of 1812 and the Mexican-American War.