John Hossack was born on May 26, 1841, in Ross Shire, Scotland. His family emigrated to Canada in 1842. Later, he made his way to Illinois, and in the spring of 1866 he found work on the farm of Alexander Murchison, in Stark County, Illinois. At this time, Hossack, who was one of several hired hands living on the Murchison farm, met his future wife, Margaret--the youngest child of his employer--as well as Margaret's siblings: Alex, a Civil War hero who had returned home after serving in the war; Donald, a farmer; and Jane, who still lived with her parents. John Hossack worked on the Murchison farm through the spring of 1866, left the farm for a short period, but returned a year later.
In the fall of 1867, Hossack traveled to Iowa to look for land, and he purchased 120 acres in Warren County, paying $480 in cash. He returned to the Murchison farm in November or December. It was later reported that he had been interested in Jane Murchison, but "circumstances prevailed" and he married Margaret instead. Their wedding was held on January 29, 1868, in the living room of Donald Murchison's house. A few months later, John and Margaret Hossack moved to the land John had purchased in Warren County, Iowa, and they settled in a small house on the farm. John Hossack's elderly parents joined them and lived there until they both died a few years later.
John Hossack established himself as one of the county's most successful and prosperous farmers. To his family, Hossack could be moody and argumentative--he often clashed with his wife and children over how the household was run and what the children were allowed to do--but he was well-respected by his fellow farmers. He took a leadership role in his church, ran for political office, and served as a trustee of the county. On Thanksgiving Day 1900, the Hossacks hosted a party at their farm for more than twenty people. John Hossack was murdered two days later, attacked in the middle of the night while he slept in his bed. His violent death shocked the county.