2. The cotton gin. Invented by Eli Whitney in 1793, the cotton gin was a machine that quickly and easily removed seeds from cotton fibers. This made cotton a more profitable crop to grow, and it led to the expansion of the cotton industry in the United States.
3. The telegraph. Invented by Samuel Morse in 1794, the telegraph was a device that allowed people to send messages over long distances using electrical signals. This was a major breakthrough in communication technology, and it helped to connect people around the world.
4. The hot air balloon. Invented by the Montgolfier brothers in 1783, the hot air balloon was a type of aircraft that was lifted into the air by heated air. This was the first time that humans had been able to fly, and it opened up new possibilities for exploration and transportation.