By 1800, the United States was a participant in the Industrial Revolution. Samuel Slater, a British mill worker, provided plans for the first American textile factory-in Pawtucket, Rhode Island. Business leaders in the Northeast quickly built more factories. This industrialization spurred the growth of cities in the Northeast.
At the same time, American settlers streamed into the Western frontier. Three different sections of the country soon developed-the North, the South, and the West. Sectionalism sparked arguments over the spread of slavery. The Missouri Compromise of 1820 calmed the debate in Congress.
Spanish and Portuguese colonies in Latin America fought for independence. The United States quickly recognized new nations formed there. In 1823, the president issued the Monroe Doctrine, warning European powers to stay out of the Western Hemisphere.
