I. Three innovations that changed life in the United States in the late nineteenth and early twentieth centuries were the telephone, airplanes and the automobile.
II. Henry Ford's most important invention was the automobile, and it changed life in the United States. Henry Ford's idea was to build an automobile so cheap that almost everyone could afford one. Ford designed several cars before he finally designed the Model T that was powered by gasoline. Then he took Eli Whitney's ideas of interchangeable parts and adapted it to cars so the parts could be used on all Model T's. Next, Ford took the factory system and made it work even better by adding a moving belt, called a conveyor belt that brought the car parts to the worker. Ford's assembly line made it possible for factories to produce goods cheaper so more people could afford them.
III. Alexander Graham Bell was a scientist, inventor, engineer and innovator and his invention of the telephone, changed life in the United States. As a child he loved to invent things. His first invention was a homemade device to dehusk wheat which was put into operation and used for years. While Bell was a professor at Boston University he built a device that let his deaf students see speech in the form of sound waves. Bell later invented an acoustic telegraph and the following year he invented the telephone. Finally, Bell brought home a working model of his telephone. He amazed his guests and his family when from his home they heard people reading and singing on the telephone from the town of Brantford which was four miles away. Bell has been described as one of the most influential figures in human history.
IV. Orville and Wilbur Wright invented and built the world's first successful airplane and it changed life in the United States. They built a wind tunnel and tested 200 differently shaped wings. The first machine they tested was a glider. Next, they built and tested a biplane with Orville lying flat on his stomach on the...