They were the OGs of Wall Street—the best American businesses selected for the country's very first stock index. On May 26, 1896, journalist Charles Dow developed the concept of tracking industrial stock prices to help gauge the health of the U.S. economy. So was born the Dow Jones Industrial Average (DJI), which remains one of the most commonly discussed stock market benchmarks to this day. Building on an earlier railroad-focused average, Dow compared his newest industrial average to sticks in the sand ...