The new spirit of nationalism affected many parts of American life after the War of 1812. People moved farther West and took more land from the Native Americans. This led to calls for improved internal improvements in order to move raw materials in the West to the new factories in the East. After the era of Good Feelings, one of the key debates in the United States was who was to supply these internal improvements—the federal government or the states?

The rise of American industry led to more calls for tariffs in order to protect American manufacturers from European competition—mainly competition from Britain. Manufacturers were in favor of tariffs, while places that produced raw materials, such as the South which was becoming a Cotton Kingdom, disliked the tariffs because it made prices higher on consumer goods.

Increased trade and transportation improvements also led to a newfound focus on commerce. In the court case Gibbons v. Ogden in 1824, the Supreme Court ruled that states cannot interfere with Congress's power to regulate commerce. This case would have never reached the courts if American commerce did not grow considerably after the War of 1812.

In order to pay for a larger military and internal improvements, many people favored a continuation of the Bank of the United States. Westerners distrusted this bank because they said it put more power in the Northeast and they also stated that it was unconstitutional. One of Andrew Jackson's key policy decisions was not to renew the bank's charter. This ultimately led to financial collapse in 1837 under his successor, Martin van Buren.

After the War of 1812, the United States experienced unprecedented growth. Much of this growth was also tied to the economic and transportation sectors of of the economy. This growth and a new spirit of nationalism helped to shape the American identity in the years leading up to the Civil War.

The War of 1812 (1812–1815) did not settle the issue for which it was fought: freedom of the seas. However, the US emerged from the conflict with a heightened sense of patriotism and economic confidence. Because of Andrew Jackson's important victory at New Orleans in 1815, Americans mistakenly believed they had won the war.

The conflict led to the development of more manufacturing in the United States. American-made products replaced ones that had been manufactured in Britain. The development of domestic industries led to a call for higher tariffs to keep out foreign-made products.

Another economic result of the war was in the banking sector. Paying for the war had been difficult because the United States did not have a national bank. Because of this, President James Madison authorized the Second Bank of the United States.

The war was the last conflict between America and Britain. Subsequent disputes were handled by arbitration, so the war led to an increased reliance on international law.

The spirit of nationalism after the War of 1812 caused the United States to pursue a nationalist economic agenda. This agenda was named the "American System" and was advocated by Henry Clay and others.

Part of the American System involved building roads and canals to further American industrial development. Most of these roads and canals were financed by states (such as the Erie Canal in New York state), as the federal government did not think that this type of construction was part of its mission. The second part of the American System was passing high tariffs that taxed foreign goods that were imported into the United States. The tariffs were intended to protect and promote American industry.

In terms of judicial policies, the Supreme Court began to pass a series of laws that dealt with contracts. For example, in the case Dartmouth College vs. Woodward (1819), the state of New Hampshire attempted to make Dartmouth a public university, but the Supreme Court said that the state had to abide by the original charter, or contract, which had made Dartmouth private. This case and others like it furthered the development of American business by protecting the sanctity of contracts.