March 15, 1862
The Fifth, Sixth and Seventh batteries left the state for St. Louis.
The regionGrade A · 1 independent source
The evidence
“Pinney, was mustered in on the ist of October, 1861, at " Camp Utley," leaving the State for St. Louis, on the 15th of March, 1862, one hundred and fifty-five strong. The Sixth battery — Captain Henry Dillon- — was mustered in on the 2d of October, 1861, at " Camp Utley," leaving the State for St. Louis, March 15, 1862, with a numerical strength of one hundred and fifty-seven. The Seventh battery — Captain Richard R. Griffiths— was mustered in on the 4th of October, 1861, at " Camp Utley," and proceeded on the isth of March, 1862, with the. Fifth and Sixth batteries to St.”
1879-history-of-rock-county/02-wisconsin-as-a-state.md, PDF p. 80
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
On the printed page (PDF p. 80) · open the whole page