The 9/11 terrorist attacks had a significant negative impact on the United States economy, leading to a sharp decline in stock markets, decreased consumer confidence, increased government spending on defense and security, and a slowdown in economic growth. The attacks resulted in massive job losses in industries such as airlines, tourism, and construction, and also led to increased costs related to increased security measures and insurance premiums. Overall, the attacks caused a temporary economic downturn, but the economy eventually recovered in the years following the attacks.
