May 13, 1857
A marriage took place at Flak (in his native land) to Miss Martha Wallesverd; the couple then returned to Beloit.
Nation and worldGrade A · 1 independent source
The evidence
“In 1857 Mr. Thompson went back to his native land, and there, at Flak, on May 13, married Miss Martha Wallesverd, and with his bride returned at once to Beloit, arriving the following”
1908-brown-rock-county/34a-biographical-1.md, Vol. 2, PDF p. 327 / book p. 824
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