Telegraphs helped people communicate and react to situations quicker than ever before. With telegraph lines installed from Boston to eastern Kansas, the Union and confederate armies could communicate with the front lines much quicker than before. Allowing troops to be reinforced in the proper place much faster than before. Telegraphs also allowed news to be communicated much quicker than before. Allowing newspapers and government officials to react and take action much faster.
In conjunction with the telegraph, railroads allowed the front lines to be reinforced with both troops and supplies at speeds never before seen. Armies could transport troops across the country to the front lines in days instead of weeks (pending on location). Train were restricted to the amount of tracks laid, and if sabotaged became death traps. The union army under Sherman's command was notorious for twisting railroad tracks around telegraph poles, making the line useless.