August 17, 1848
Surveys were commenced in Rock county for the Rock River Valley railroad.
Rock CountyGrade A · 1 independent source
The evidence
“In January of this year a large public meeting was held at Janesville to promote the project of a railroad coming into Janesville. The Madison & Beloit Railway Company had been incorporated at the first session of the legislature in 1848. On August 17 surveys were commenced in Rock county for the Rock River Valley railroad, under charge of Colonel Hugh Lee and A.”
1908-brown-rock-county/26-history-of-janesville.md, Vol. 2, PDF p. 28 / book p. 542
Brown, William Fiske, editor. Rock County, Wisconsin: A New History of Its Cities, Villages, Towns, Citizens and Varied Interests, from the Earliest Times, Up to Date. Chicago: C. F. Cooper & Co., 1908. 2 vols. archive.org/details/rockcountywiscon01brow, archive.org/details/rockcountywiscon02brow.
Grade A: Found on a page of one of our sources