John Harris was born in Crow's Nest, St. Cleer, Cornwall, the son of Joseph Blamey and Mary Ann Bennett Harris. He is listed in the Cornish Mining index as a copper miner, age 14, but by the 1871 census his family had moved to County Durham in the far north of England. On March 21, 1874 he married Elizabeth Jane Hill in the Parish of St. Nicholas, Newcastle-upon-Tyne, Northumberland, nine days after his seventeenth birthday. They had told the vicar of St. Nicholas that they were 22 and 21, when in fact they were only 17 and 14. The following year their first son Joseph was born, one day after his father's 18th birthday. Between 1875 and 1902, John and Elizabeth produced a total of 23 children, 16 of whom lived past infancy. Their names were Joseph Blamey, Mary Ann, Ada Jane, John Charles, Louisa Ellen, Beatrice Jessie, Florence Maud, Emma Ursula, Thomas Crocker Hill, Lily, Peter Robert, Andrew, Sarah Elizabeth, Laura Ethel, Redvers George, and Gertrude Alice.

John continued to work as a coal miner, and the family relocated fairly often in both County Durham and Northumberland. In 1895, oldest son Joseph emigrated to the U.S. with his wife and family. In 1904 John, Elizabeth and their ten youngest children also emigrated to the U.S. aboard the SS Saxonia, arriving in Boston on May 19, 1904. John filed an Intention of Naturalization on August 24, 1907, and was naturalized in 1910. The older, married Harris children eventually emigrated too, except for Mary Ann. The passenger manifest of the Saxonia states that the Harris family was headed to Illinois, where son Joseph lived. They appear to have stopped in Missouri, where three of their children married, before moving to Iowa. In Iowa they lived in Foster, Albia, Woodward, and the Dallas Coal Camp. John died in a hospital in St. Louis Missouri after undergoing surgery for cancer. He was buried next to his wife Elizabeth, who predeceased him.