Various records indicate that John W. Miles was born about 1843, in either Coffee County or Franklin County, Tennessee. The year of birth carved into his grave marker is almost certainly incorrect, as is the birth date on his death certificate, the information for which was provided by a son-in-law with who John W. Miles was residing in Greenville, Texas when he died. The dates on the marker do not even match those on the death certificate, which state that he was born on 14 December 1837 and died on 17 May 1928, and was buried on 19 May 1928. (The marker says he was born 4 December 1837 and died 27 May 1928.)

John W. Miles had four wives, although he may or may not have been legally married four times. His first wife was Ophelia Mitchell, who he married about 1867, and with who he had one son, William A. Miles, born in 1869. In adulthood, William A. Miles lived in Morgan County, Alabama. The three are enumerated in the 1870 federal census for Franklin County, Tennessee.

His second wife was Kate Piggean, who he married in Franklin County, Tennesee after his first wife presumably died. He and Kate and son by first wife are enumerated in the 1880 census for Franklin County, Tennessee. In 1884, John divorced Kate on the grounds of her adultery, although there is evidence that he was likewise adulterous.

John's third wife was Margaret Elizabeth Hodge, who he married on 10 October 1884 in Franklin County, Tennessee. The couple had one child, Charles ("Charlie") Wesley Miles, born 18 August 1885.

In December 1885, John abandoned Margaret and son Charlie and went to live in Alabama (probably Lowndes County) with Mary Alice Hefner, with who he already had three children. No evidence has yet been found to confirm that he and Mary Alice were ever legally married. After two more children were born in Alabama, the couple moved with their children to Texas, about 1893. Four more children (for a total of nine) were born in Texas between 1893 and 1902.

There is evidence that they may have initially resided in Johnson County and Ellis County before settling on a 100-acre farm about 3 and 1/2 miles west of the Collin County community of Josephine. In 1901, the family moved to a 160-acre farm in neighboring Hunt County, about on mile east of Josephine. In 1915, a year before Mary Alice died, John W. bought a city lot in Josephine.

The 1920 federal census lists John W. as living in Josephine with the only other member of the household being his youngest daughter, Pauline.

He died on 17 May 1928 at 3904 Simond Street, Greenville, Hunt County, Texas.