In tracing our line from Carl Lathrop to Rev. John Lothropp, the path is clear and well documented, except for the details of Russell Lathrop's father, Rev. Elkanah Lathrop, Carl's G3-grandfather.
Elkanah Lathrop's name appears in several documents which prove he existed, but the evidence of his children is less direct, and there is no mention of his wife's name anywhere (yet)!
The path from Rev. John to Elkanah is traced in A Genealogical Memoir of the Lo-Lathrop Family in This Country, Embracing the Descendants, as Far as Known, of the Rev. John Lothropp, of Scituate and Barnstable, Mass., and Mark Lothrop, of Salem and Bridgewater, Mass. and the First Generation of Descendants of Other Names under the children of Ezra Lathrop and Charity Perkins:
Elkanah is mentioned in two books in sections focused on some of his descendants. Exerpt from Portrait and Biographical Record of Effingham, Jasper and Richland Counties Illinois, Containing Biographical Sketches of Prominent and Representative Citizens, Governors of the State, and the Presidents of the United States in the section on Henry Lathrop Sr. (our ancestor):
Exerpt from A Genealogical and Biographical Record of Decatur County, Indiana: Compendium of National Biography in the section on James B. Lathrop (Ezra > Erastus > Elkanah):
Additional evidence:
Elkanah appears in the 1790 census of Fairfax, VT in what was then Chittenden County, now Franklin County. Listed are 1 male 16+ (Elkanah); 4 males under 16; and 1 female. In 1790, the ages for the known children are: Erastus 13/14, Ezra 8/9. Hannah and Russell were born after 1790, so the 1 female is likely Elkanah's wife.
In 1795, Elkanah is named as the trustee for one of 6 initial school districts in Fairfax.
From Fairfax, Elkanah apparently removes with his family to Sutton, Canada, probably around 1799/1800 when Elkanah appears on a land sale in Fairfax. Two of his grandsons, Erastus' sons Augustus and Ezra, are born in Sutton in 1801/1803.
Sometime around 1810, near the time the British government began confiscating land in Canada prior to the War of 1812, the family returns to Vermont, this time to Richford. It is here that Elkanah's daughter Hannah marries Daniel Janes in 1811, and his son Russell marries Cynthia Powell in 1815. It is unclear if Elkanah is still alive by Russell's wedding.