Dynamic Change In The U.S. There was much change brought about by the Civil War, and many people and companies played very big roles throughout this enormous growth of our country. The U.S. basically erupted economically during this time, and the tremendous augmentation of railways only instigated this bursting of the economy. Not only did the U.S. have stunning economic growth and railroad production, but it was overwhelmingly influenced by many key individuals such as Gustavus Swift, Thomas Edison, Andrew Carnegie, John Davidson Rockefeller, and John Pierpont Morgan. Each of these men played exclusive roles during this extremely successful period of our country.