In the days before modern transportation, telephones, and TV, messages and products had to arrive on foot. Consider that the Battle of New Orleans took place after the War of 1812 was over — the news of peace was a little slow getting around. You could own the best crops or raw materials in the world, but having stuff to sell wouldn't do you any good if you couldn't get it to where somebody was ready to buy it. In the early days of the U.S., transportation moved as slowly as it had thousands of years earlier in the Roman Empire.
Several inventions helped the U.S. grow. In 1838, an Illinois blacksmith named John Deere invented the steel plow, good for helping grow crops. For harvesting crops, Pennsylvania farmer Cyrus McCormick invented a mechanical thresher that did the work of 15 men. A New York painter named Samuel Morse invented the telegraph in 1844, and the world became instantaneously connected. In new factories, the same kind of steam engines that chugged along in boats and trains helped run manufacturing equipment.
These inventions changed the world more than battles, bills, or presidents did. They're concrete examples of the non-political themes that will be the key to your success on the AP U.S. History exam.
Factory jobs and the American Dream
Commuting wasn't really an issue before the Civil War. Most people worked where they lived: down on the farm. Sounds nice now, but back then for a lot of people it meant boredom and little money. With improved transportation for products and steam power to run machines, factories in New England began making cloth, tools, and guns. For example, the whole town of Lowell, Massachusetts, popped up around a cloth factory that supplied jobs for hundreds of Lowell girls who came from farms and immigrant ships beginning in 1813. The Lowell system (1815) guaranteed these girls safe living conditions and food as long as they worked from dawn to dusk six days a week, almost twice as long as people work today.
People chose to work in factories and stores because, hard as the work was, it gave them some freedom to change their lives. Before the Industrial Revolution, most of the money and power belonged to the people who owned land. People were stuck where they were born: lucky landholder or landless farm laborer. The Industrial Revolution gave people the chance to move around, change jobs, and maybe even save up enough money to start a small business. Most poor people stayed poor, but some of them managed to get ahead; in the U.S., no fixed social classes held them back. The Industrial Revolution, with all its pollution and overwork, was the beginning of the American Dream.