March 21, 1843
The town of Fulton was organized by act of the legislature.
Nation and worldGrade A · 1 independent source
The evidence
“lature to organize their town, to be called Franklin. There being another town by that name, they changed it to Fulton and passed the act of organization March 21, 1843. The first Tuesday in April, 1843, the voters of the town (some twenty in number) met at the house of William B. Foster and held their meeting, electing George B.”
1908-brown-rock-county/31-smaller-cities-villages-towns.md, Vol. 2, PDF p. 179 / book p. 685
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