Improved communications also contributed to economic expansion. The railroad improved mail delivery, replacing the stagecoach. The invention of the telephone and the telegraph afforded the rapid communication essential to business operations. This business boom triggered a sharp increase in investments in the stocks and bonds market. As businesses prospered, persons eager to share in the profits invested heavily, providing capital needed to for expansion. Banks also contributed to the nation's economic growth by making loans to businesses.

The expansion of industry had a profound effect on American life. As new businesses sprouted in cities metropolitan populations reached unprecedented numbers. During this period many Americans amassed huge fortunes from the business boom, while others lived in extreme poverty. The sharp contrast between the rich and the poor and other features of American life stirred widespread discontent triggering new reform movements. Little was done to regulate businesses...

Business executives formed monopolies in order to wipe out competition and gain complete control of their industries. These monopolies had some favorable effects on the economy, helping make corporations efficient and contributing to economic growth. They also enabled businesses to avoid sharp fluctuations in price and output keeping prices steady.
On the other hand, monopolies gave some business leaders so much power that they could take unfair advantage of others. A business executive with little or no competition could demand goods from suppliers at low cost, while charging high prices for the finished product. The executive could also save money by reducing a product's quality. Measures to aid the poor and control the size and power of big business among other things were introduced as a result.

The United States' role and influence in foreign affairs also began changing during the late 1800's and early 1900's as the country built up its military strength and became…