April 6, 1854
The Murray block in Beloit burned
BeloitGrade A · 1 independent source
The evidence
“Murray block (S. W. corner of Turtle and Race streets) burned on the morning of April 6, 1854, Mr. Carpenter hastily placed his money and valuable papers in a wooden box and hid it under his front sidewalk.”
1908-brown-rock-county/23-beloit-banking.md, Vol. 1, PDF p. 526 / book p. 487
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