I had an epiphany of sorts... I'm working on other Groats and have come across Stillman P., in Broken Bow, NE. Then I saw this today in another post:
1851 Canada West Census, North Dorchester, Middlesex, Ontario Groat, Preston49M Mar.FarmerCanadaBaptist Liv. in frame house Liddy47F Mar.F" one story, one family Elizabeth18F Sing.F" Allismince16F "F" Tilman P.13M "F" Thomas10M "F" Charles3M "F"
There's "Stillman P." but missing the 'S' and an 'l'. Anita Alexander notes that the family appears to go on to MI (the Preston GROATS).
Stillman P. Groat, who owns and occupies one of the finest homes in Broken Bow, Nebraska, is widely and favorably known as an enterprising and successful business man and a public-spirited citizen, being interested in all that affects the progress and welfare of his county and state. He is a native of the Province of Ontario, Canada, born January 2, 1839, a son of Preston and Lydia (Marsh) Groat, and sixth of their eight children. The parents were natives of Quebec province, the father of Scotch and the mother of English extraction, and both died in Michigan, he in 1886, at the age of eighty-one years, and she, in 1874. Besides Stillman P., those of the children now surviving are: Charles, of Chicago; and Mrs. Amanda Lazier of Michigan. (read more at the above link)
... and then don't miss out that he was a murderer perhaps...
Oxley always proclaimed his innocence and the fact that he was unjustly charged, tried, and convicted. It turned out that Oxley really was innocent; he served less than 2 years in the Nebraska State Prison at Lincoln, because the real murderer confessed to the murder on his deathbed. This mans name was Stillman P. Groat, the father of William Groat, and Mr. Fullharts neighbor Further information on Stillman Groat is sketchy, but some very real motives for the murder are the long-standing feud between the two neighbors, money, or possibly they got into a new argument.
Finally, from the "Groat Gazette" an epilogue to the NE info: