His father Harmon A. Hays fought in the War of 1812, naming his son for a relative by marriage, Colonel John Coffee.

Sam Houston appointed him as a member of a company of Texas Rangers because he knew the Hays family from his Tennessee years.

In 1840 Tonkawa Chief Placido and 13 scouts joined with the Rangers to track down a large Comanche war party,[3] culminating at the Battle of Plum Creek.

[10] When son John Caperton Hays married Anna McMullin in San Francisco, two Texas Ranger legacies were combined.

[11] John Hays Hammond, Jr., was an apprentice to Thomas Edison and worked with Nikola Tesla; he was on the board of directors for RCA.

In 1849, Hays was appointed by the United States government as the US Indian agent for the Gila River country in New Mexico and Arizona.

In 1876, Hays was elected as a delegate to the Democratic Party national convention, which nominated Samuel J. Tilden for the presidency of the United States.

[4] John Hays died in California on April 21, 1883, and his remains were interred at Mountain View Cemetery in Oakland.