On April 9, 1868, Johnson married Mary Elizabeth (, born January 1847) in Worcester;National Archives and Records Administration, 1870, August 18. 1870 U.S. census, population schedules: Worcester Ward 4, Worcester, Massachusetts, roll M593_658: p. 223B: image 483: lines 13-20.National Archives and Records Administration, 1880, June 8. 1880 U.S. census, population schedules: Worcester, Worcester, Massachusetts, roll 567: p. 122D: enumeration district 884: image 0542: lines 22-27.National Archives and Records Administration, 1900, June 6. 1900 U.S. census, population schedules: Fitchburg Ward 2, Worcester, Massachusetts, roll T623_691: p. 9A: enumeration district: 1609: lines 13-14 & 20-23.National Archives and Records Administration, 1910, April 25. 1910 U.S. census, population schedules: Fitchburg Ward 2, Worcester, Massachusetts, roll T624_628: p. 10A: enumeration district 1728: image: 158: lines 70-76. and the couple had three sons, Frederick Iver, John Lovell and Walter Olof, and two daughters, Mary Louise and Nellie.
