1840
Easton and Gusta Johnson arrived in Rock county and settled in Avon township.
Rock CountyGrade A · 1 independent source
The evidence
“Rock county, Wisconsin, where he was born April 20, 1859. His parents, Easton and Gusta Johnson, were both natives of Norway, but hearing of the advantages to be gained in the United States, they left their native land and sailed for America, arriving in Rock county in 1840, and settled in Avon township on the farm now owned by our subject. They had a family of five children, three of whom are living, viz. : Lizzie, Jennie and our subject.”
1908-brown-rock-county/34c-biographical-3.md, Vol. 2, PDF p. 459 / book p. 947
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