[4] He developed a series of principles for understanding and analyzing market behavior which later became known as Dow theory, the groundwork for technical analysis.

[5] The stock price average was created on July 3, 1884, by Charles Dow as part of the "Customer's Afternoon Letter".

At its inception, it consisted of 11 companies—9 railroads and 2 non-rail companies, Pacific Mail Steamship and Western Union Telegraph.

It was in this column that he often put forward his ideas of stock price movements, which were the foundation of what was later called the Dow Theory.

[9] At age 30, having moved to New York City the prior year to accept a job offer, Dow married his wife Lucy, who had a daughter from a previous marriage.