Look at the records on LDS Family Search website-https://familysearch.org/
John Merrill- ID# LDHH-2V2
There is a census record for 1870 that shows John, his wife and children living in Wisconsin.
"United States Census, 1870," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MNS3-26Y : accessed 31 Dec 2013), John Merrills, Wisconsin, United States; citing p. , family 113, NARA microfilm publication M593, FHL microfilm 000553232.
Also, there is a census record for 1880 in Wisconsin, but their last name is misspelled.
"United States Census, 1880," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MNHD-RX4 : accessed 31 Dec 2013), John Merrilly, Waterford, Racine, Wisconsin, United States; citing sheet 529A, family 0, NARA microfilm publication T9-1443
There is also a Pedigree Resource File.
"Pedigree Resource File," database, FamilySearch (http://familysearch.org/pal:/MM9.2.1/395S-FY2 : accessed 2013-12-31), entry for John /Merrill/.
Hope this will help,