1857
J. Pierron located in Beloit; he brought his family in the fall of the same year.
BeloitGrade A · 1 independent source
The evidence
“J. PIERRON, contractor and builder; born in Department Muerth, France, April 4, 1825; came to America, May, 1817 ; went to Syracuse and was there ten years, working at his trade as carpenter an 1 builder ; after moving to several places, finally located in Beloit, in 1857 ; brought his family in the fall of same year ; it was hard to find work enough to support his family at first, but, after hard work and much perseverance and frugality he did well, and, in 1862, went into business on his own account and has accumulated a comfortable property ; owns four houses and shop ; when he first came could neither read nor write the English language, and worked under some disadvantages. Married Olive Rousch, a native of Prance, May 6, 1852 ; have three children ;”
1879-history-of-rock-county/18-bios-beloit.md, PDF p. 757 / book p. 761
Butterfield, C. W., et al. The History of Rock County, Wisconsin: its early settlement, growth, development, resources, etc. Chicago: Western Historical Company, 1879. Cornell University Library via the Internet Archive, archive.org/details/cu31924028871585.
Grade A: Found on a page of one of our sources