I believe Leopold was born in Ruit, Karlsruhe, Baden, Germany, and was baptized under the name Leopold Peter (not John!) Speer on 4 March 1844 at the Evangelisch church. His birth date was 27 February 1844. Only his mother's name was given in the record, Katharine. See this familysearch.org search result:https://familysearch.org/search/record/results#count=20&...
Further searching at that location via familysearch shows that Katharine also had other children: Katharine Magdalene (b. 20 Nov 1838), Johann (b. 03 Jan 1843), and Salamo (b. 06 Dec 1848.)
The 1900 census says that Leopold immigrated in 1852. At age 8, one assumes there was some family with him. I've never been able to find an immigration record under the name Leopold, but I have not tried Peter.