The war changed the economical balance of the world, leaving European countries deep in debt and making the U.S. the leading industrial power and creditor in the world.
The First World War destroyed empires, created numerous new nation-states, encouraged independence movements in Europe’s colonies, forced the United States to become a world power and led directly to Soviet communism and the rise of Hitler. Diplomatic alliances and promises made during the First World War, especially in the Middle East, also came back to haunt Europeans a century later. The balance of power approach to international relations was broken but not shattered. It took the Second World War to bring about sufficient political forces to embark on a revolutionary new approach to inter-state relations.
The most difficult task confronting many Southerners during Reconstruction was devising a new system of labor to replace the shattered world of slavery. The economic lives of planters, former slaves, and nonslaveholding whites, were transformed after the Civil War.
The Spanish colonists could have helped the American Indians adapt to the new species of livestock by teaching them to fence their fields to protect their crops. Furthermore, they could have taught American Indians how to use livestock for food, trade, and labor.