Francis Armstrong (1839-1899) through his labors became one of the richest and most prominent citizens of Salt Lake City. He journeyed to Salt Lake City in 1861 shortly after converting to the Church of Jesus Christ of Latter-day Saints (LDS Church). He worked several jobs in the Salt Lake valley, from lumber mill to flour mill, before he joined the Little Lumber mill in 1862. With his skill
Francis quickly rose to the position of mill manager. In 1864, Francis married Isabelle Siddoway (1849-1930), whom he had met when he worked with her father. Isabelle had traveled with her father and brothers to Salt Lake City in 1860 after the death of her mother. Isabelle met Francis when he lodged with the Siddoways. They raised a family of twelve children, although the first son died when he was three years old. By 1870, Francis was able to buy the Little Lumber mill. Through much hard work, the lumber mill became a great success. This success allowed Francis to invest in other businesses in Salt Lake City. As a result he became one of the wealthiest citizens of the city. At this time, Francis was called by the LDS Church to take a second wife, Sarah Carruth. They had six children together, but only two survived to adulthood. Sarah Carruth passed away thirteen years later in 1883. The two surviving children were raised by Isabelle. The wealth also enabled Francis to purchase a large plot of land at Seventh East and First South. On part of the land, he constructed the Armstrong Mansion, which still stands today. The rest of the land was set aside to give Francis and Isabelle's children places to build houses if they so wished. Besides business affairs, Francis was involved in politics. He served on the Salt Lake City School Board and City Common Council before he became mayor in 1886. During his tenure, he hid several LDS general authorities who were on the run from US Marshals for being polygamists. Francis also brought some unique touches to Salt Lake such as the electric trolley service and having one of the first houses to have indoor plumbing. By his death in 1899, Francis was on the board of directors for many companies, owned land in Utah and Idaho, and was one
of the most respected men in Utah.