July 15, 1838
James P. Pierce came to Wisconsin and settled in Rock County, his first purchase being eighty acres from the Government on Section 3 of Harmony.
Rock CountyGrade A · 1 independent source
The evidence
“Pierce, died April 2, 1878 ; is buried at Rock River Cemetery; his mother, Susan Pierce, is still living, 87 years old ; James P. came to Wisconsin July 15, 1838, and settled in Rock Co. ; his first purchase was eighty acres from the Grovernment on Section 3 of Harmony. Married, Sept. 24, 1840, Olive Hall, daughter of Gardiner and Mary 1847;”
1879-history-of-rock-county/25-bios-milton.md, PDF p. 822 / book p. 826
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