During war it is very important for a general to talk to his soldiers and give them command or higher government officials who can provide information to the commanding officers to make the best judgment during the war. According to the American Civil War website History.com, Abraham Lincoln was the first president to use the telegraph to communicate with his officers on the battlefield. In 1861, the Union Army established the United States Military Telegraph Corps, led by Andrew Carnegie, the railroad man. Over the next year, the USMTC trained 1,200 operators and sent over millions of messages to and from the battlefield. Technology has changed the way humans communicate. In today's world, emails, Facebook, Twitter and many other social media are not only used for communication, but also to promote businesses, non-profit organizations and many other events. Therefore, communication is necessary, no matter the medium or means. From pictograms to Instagram technology, the way humans have changed