At the close the Dow was 0.1% lower at 19,918, the broader S&P 500 was down 0.2% at 2,260 and the Nasdaq was 0.4% lower at 5,447.
With a 2% fall, Wal-Mart was one of the big losers.
Investors stepped back from a recent rally fueled by optimism that President-elect Donald Trump will invigorate economic growth.
Analysts said the market appears to be winding down before the holiday period.
The Dow Jones Industrial Average continued to back away from Tuesday's record close.