Answer: The Great Depression of the late 1920s and ’30s remains the longest and most severe economic downturn in modern history. Lasting almost 10 years (from late 1929 until about 1939) and affecting nearly every country in the world, it was marked by steep declines in industrial production and in prices (deflation), mass unemployment, banking panics, and sharp increases in rates of poverty and homelessness. In the United States, where the effects of the depression were generally worst, between 1929 and 1933 industrial production fell nearly 47 percent, gross domestic product (GDP) declined by 30 percent, and unemployment reached more than 20 percent. By comparison, during the Great Recession of 2007–09, the second largest economic downturn in U.S. history, GDP declined by 4.3 percent, and unemployment reached slightly less than 10 percent.
