I found some information about your great-grandmother Elisa LOHFF! She married John MACKIN June 2, 1885 in Dane Co., Wisconsin. Based on evidence from the 1870 U.S. Census, she was the daughter of Henry and Frederikke or Frances LOHFF of Springdale, Dane Co., Wisconsin and was born, as you said, in 1861. Henry and Frederikke/Frances were from Mecklenburg Schwerin. Henry was born about 1810 and apparently died between 1870 and 1880. Frederikke/Frances was born about 1817 and apparently died between 1880 and 1900. From the evidence of the 1860, 1870, 1880, and 1900 U.S. federal censuses, they had three sons and four daughters: Charles (also known as Hans Charles, born about 1841 in Mecklenburg), Frederic (born about 1844 in Mecklenburg, married Mary BECHLET), Wilhelmina (also known as Mina or Minnie, born about 1846 in Mecklenburg, married Charles ELVER), Betty (also known as Betsy or Bette, born about 1850 in Mecklenburg), Henry (born about 1856 in Wisconsin, married Lizzie ____), Emma (born about 1859 in Wisconsin, married Charles L. BOECK), and Elisa. In 1855, the Wisconsin census recorded that Henry was living in Blooming Grove township, Dane Co. In Springdale, Henry was a farmer; in 1860 his real property was worth $2,200, and in 1870 it was worth $7,000.
Coincidentally, in 1880, Elisa's brother-in-law Charles ELVER was a farmer/miller in Vermont township, Dane Co. The family enumerated next to him was headed by William DENEEN and included John MACKIN (age 22) "working at grist mill."