This source demonstrates the impact of what 19th century historical development in the united states?

Several important changes took place in the late 19th century. First, around 1870, Germany became the new leader in European industry. Germany far exceeded the production of any other European nation in chemicals and electrical equipment. The nation continued to expand its trade networks and soon enjoyed a flood of new plants and factories. Great Britain tried to retake its position as industrial leader, but Germany would not give up its newly acquired title so easily. The United States also enjoyed success during the Second Industrial Revolution. In fact, industry had made the U. S. the richest nation in the world at this time.