Granville Woods improve the telegraph by allowing a telegraph station to send and receive voice and telegraph messages over a single wire.
He also invented the Multiplex Telegraph which allowed the train stations to sent messages to moving trains.
Explanation:
He was an American inventor, the first African American to be a mechanical and electrical engineer after the Civil War. His Multiplex Telegraph assured a safer and better public transportation between the cities of the United States.
Explanation: Without something being written down as a law to follow through with people could do whatever they wanted. But Lincoln was smart and he pushed for the 13th amendment so that everyone in the United States was forced to oblige.
