longest recession in U.S. history was the Great Depression, which lasted from August 1929 to March 1933, a duration of 3 years and 7 months
average length of a recession in the United States has varied over time. Since 1854, the average recession has lasted about 17 months.234+2 However, since World War II, the average duration has shortened to approximately 10 months
The longest bear market in U.S. history occurred from 1973 to 1974, lasting 630 days, or about 21 months.23 During this period, the stock market declined by about 48%.