The Hansen family emigrated from Denmark in 1864. They sailed on the General McClellan, and arrived in New York on 23 June 1864. In some sources Hansen is sometimes spelled as "Hanson." At some point the Hansen family changed the surname to Peterson. In the 1870 Census, Johanna and her brother share the surname of "Peterson" while her parents and cousin were still listed as "Hanson."
The name engraved on her tombstone and which appears in the 1880 Census is "Hannah Christopherson."