THE TELEPHONE: Alexander Bell's father was a teacher of the deaf. Bell invented the first hearing aid around 1875. When a wire connected two of these devices, the telephone was born. Its first successful test came in 1876. By 1900, 1.5 million homes had phones. Long distance came in 1892. Bell formed American Telephone and Telegraph (AT&T), which became one of America's longest lasting monopolies.

FARMING: Cyrus McCormick invented the REAPER, which harvests grain, in 1831. He bought out all competition and bought new inventions before he died in 1884. His INTERNATIONAL HARVESTER CORP. became the largest producer of farm equipment, helping the US lead the world in INDUSTRIAL AGRICULTURE.

ELISHA OTIS: Invented the elevator, which was perfected in 1852. With competition from Westinghouse he improved his elevator, which allowed the creation of the SKYSCRAPER and deeper mining operations. Taller office buildings, along with the TYPEWRITER, invented by Christopher Sholes in 1867, caused an improvement in business operation and efficiency. As buildings went higher, cities grew larger a process called URBANIZATION.