At the close, the Dow Jones industrial average had lost 1.6 percent, the broad S&P 500 index 1.4 percent, and the technology-heavy Nasdaq composite index fell 1.5 percent.
Behind the red numbers is, among other things, growing concern about the price of oil, which has taken a significant step upward - late Wednesday evening, a barrel of Brent oil was trading at just over $109.
The Federal Reserve announced, as expected, that the key interest rate would be left unchanged.
But it was also noted that the war against Iran will have consequences for the economy, while outgoing Fed Chairman Jerome Powell said he had lowered his expectations somewhat regarding the fight against inflation.
