The cotton industry was particularly important to the Southern economy. By the 1830s, cotton was the United States' leading export crop, and it accounted for more than half of the country's total exports. The rise of the cotton industry also led to the expansion of slavery in the South. By 1860, there were more than four million slaves in the United States, and they made up more than a third of the Southern population.
The steamboat also played a major role in the development of the United States after the War of 1812. Steamboats made it possible to transport goods and people quickly and efficiently along rivers and canals. This helped to open up the Western frontier and to connect the different regions of the country.
The construction of canals and railroads also contributed to the growth of the United States. Canals and railroads made it possible to transport goods and people over long distances, and they helped to connect the East Coast with the West. This stimulated the growth of trade and commerce, and it also led to the development of new towns and cities.
The period after the War of 1812 was a time of great change and growth for the United States. The country's population doubled in size, the economy grew at an unprecedented rate, and the cotton industry, the steamboat, and the construction of canals and railroads all played important roles in this growth. This period also saw the expansion of slavery in the South, which would eventually lead to the Civil War.