New Hampshire—and the world—changed a lot during the 20th century. When the 20th century began, the United States was not very involved in world events, and most people focused almost all their attention on their local communities or their state. By the time the 20th century ended, the United States was a worldwide superpower. The U.S. government had alliances with dozens of other countries. U.S. companies sold products and conducted business all over the world, selling everything from soda pop to computers. And U.S. culture—things like movies, celebrities, fashion, and music—influenced what was popular all over the world.

For the people of New Hampshire, the 20th century was a time when their attention switched back and forth between their local communities and the larger world around them. By the end of the century, New Hampshire had begun to look very much like it does today.