The Early 20th Century period was a time of economic prosperity followed by financial catastrophe. The first three presidents in this period are often referred to as the Progressive Presidents. The Progressive Era was a time of social change: women fought for the right to vote, big corporations were broken up, and labor laws changed the way we worked. After World War I, America’s economy boomed throughout the Roaring Twenties and the Jazz Age. But, after the stock market crash of 1929, we sunk into the Great Depression. The U.S. was brought into World War II after the bombing of Pearl Harbor. With the war, the country’s economy rebounded and prosperity was just around the corner. However, the atomic bomb ushered in the Nuclear Age and a period of uncertainty and instability known as the Cold War.