September 25, 1838
Lucien Churchill was quite sick, with a fit of ague.
Nation and worldGrade A · 1 independent source
The evidence
“"Nov. 23, 1837.- The Churchill boy got Ogden's ox cart to go up to Smith's to get Amanda's clothes." (Smith's were at Otter Creek, four miles east of us). "May 8, 1838. Dr. Bullard operated on Lucien Churchill's neck. "Sept. 4, 1838.-Churchill sold out his claim on the prairie to Joseph Goodrich for $125 in goods out of Goodrich's store." (This was the Carr farm). "Sept. 25, 1838.-Lucien Churchill is quite sick; had a fit of ague. Oct. 28, 1838, Amanda Churchill is sick with symptoms of ague. Oct. 23, 1838. Lucien and Amanda are no better; have got the ague regular. Dec. 18, 1838.-Ogden and Churchill went out hunting and got a fat doe and lugged it home three miles on their backs. June 10, 1839- Churchill and Ogden went to Beloit to mill with grist to get ground.”
1900-caswell-reminiscences/07-fort-atkinson-and-early-janesville.md, PDF pp. 3–27
Caswell, Lucien Bonaparte. The Reminiscences of the Hon. L. B. Caswell. Written at Fort Atkinson, Wis., 1914–1916; four-column newspaper reprint, newspaper and date unidentified. University of Wisconsin-Madison Libraries.
Grade A: Found on a page of one of our sources