On April 5, 1842, John Henry Barker was born in Wandsworth, Surrey, England to John Humphrey and Anna Maria Delap Barker. His father was a lawyer's clerk and his mother often worked as a seamstress. During his childhood, the family moved often, living in several cities in England. As a young boy, he held several jobs, working in a linen button factory and later as a waiter.

In 1848, his family became associated with the Church of Jesus Christ of Latter-day Saints. However, sometime after this, his father was sent to a "debtor's prison" due to financial difficulties, and the family was broken up, leaving only John and his mother in London.

In 1859, Barker was baptized into the Mormon church and over the next few years held many leadership positions within his local branch. He met his future wife, Susan Dermott, through this work, and in 1868 they came to America on the Manchester. They were married before starting across the plains later that year.

Arriving in Utah, the couple settled first in Salt Lake City, and then moved to Cache Valley, living in Paradise, Providence, and Newton respectively. Throughout the years he worked as a school teacher, a businessman, a miner, and a farmer. He also held many positions of leadership in both the Church and the Newton community.

Family was extremely important in Barker's life. He and Susan raised nine children in their home in Newton. In 1879, Barker entered into polygamy when he married Christena M. Benson. Together they had eight children. Later that same year, Barker married his third wife, Johanna Jensen. Their marriage produced two more children. In addition to his wives and children, Barker felt a strong connection to the family he had left behind in England. He maintained contact with his three living sisters, especially his youngest sister Jane, or Jenny as she was called.

Always an active member of the LDS church, Barker was called to serve a mission to England in 1909. The trip was too hard on him, however, because of his age and the stress of travel, and after only a few months there he was sent home. Once home, he was stricken with gangrene and had to have a leg amputated. During the recovery, he caught pneumonia, and on February 27th, 1910, he passed away at his home in Newton.