The document discusses isolationism and Republican policies in the early 20th century United States. [1] Isolationism referred to the US focusing on domestic industry and economic growth to become a global power. [2] Republican policies at the time promoted laissez-faire economics, tariffs to protect US industries, and low taxation to spur domestic consumption. [3] Together these factors and US involvement in World War I without suffering damage contributed to a major economic boom that made the US the richest country in the world.