telegraph

The telegraph completely changed how the United States communicated with each other. By speeding up the means of communication, it eliminated the total reliance on the postal service, and pony express, as well as enable even the most illiterate people to communicate across the country with out having someone else write the message.

By also having the telegraph wires go across the country, it helped to fight crime as well. By being able to send out a description of the people responsible for lets say a bank robbery, it enabled the law enforcement in neighboring towns to be immediately notified that such a crime happened, and to be on the look out for these people. This helped end the run of large gangs that ruled the "old west", and was ended by technology, or at least aided by it.

The telegraph was not the end all be all of technology, but it helped to bring on technology that we still use today, mainly the telephone, but also including the wire transfer.