In the mid-1700s, inventors in Great Britain created machinery to perform some of the work involved in cloth making. These innovations led to changes, not only in industry, but also in the way people lived. The British tried to keep their new industrial technology a secret. However, one man, Samuel Slater, memorized the design of some of the machines and then immigrated to the United States. In Rhode Island he took over the management of a cotton mill and duplicated many of the new designs. As the Industrial Revolution spread through the United States, new technology contributed to the growth of cities and agriculture.
During the 1800s Americans moved west of the Appalachian Mountains in increasing numbers. To support the movement of people and goods, roads and canals were built connecting the East with the Ohio River valley. President James Monroe won the election of 1816 by an overwhelming majority. During his first administration a spirit of unity existed throughout the country. Before long, however, this feeling of unity dissolved into regional differences.
In other areas, colonies in Central and South America rebelled against Spanish control. In 1822 Spain asked France, Austria, Russia, and Prussia for help in its fight against revolutionary forces in South America. The possibility of increased European involvement in North America led President Monroe to issue a statement declaring that the United States would oppose any new European colonies in North and South America. His statement later became known as the Monroe Doctrine.