I looked at my family tree for the names you asked about (relisted below). I did not find them.
I did trace a distant branch (7th great grandfather's brother's line) a couple years back that moved from Litchfield, CT to Missouri for a Jimmy Newton Galpin. That branch didn't have any of the individuals you're looking for that I saw. My only suggestion off hand is alternate spellings, misspellings in census often cause you to not find a record. Sometimes it's just trial and error on spellings to see if something comes up that makes sense. Good luck and wish I was more help.
Valentine Orson Galpin born 1807 Locke, Cayuga County, NY; died 8 May 1879 Burns, Allegany County, NY, lived in Burns area from about 1848 till his death.
His brother Everlin Galpin, Find A Grave # 62574831, born 1812 in NY State, Location unknown; died 18 Mar 1873 Brownstone, Wayne County, MI; buried Soop-Pleasantview Cemetery, Van Buren Township, Wayne County, MI.
Parents of Edward A "Emmett" Galpin born 31 Jul 1843 Groveland, Livingston County, NY;
RE: Bull Family in La Plata Cemetery I sure wish I could have been of more help to you locating info. on the Bull family. I use to know one family member but I don't even know where she lives today. I don't find many Bull's listed in our area phone book (only two) so most of the family has either moved or passed away.
Sorry that I cannot provide more info. about the family. I have added some info. to the memorials I created so check them out again when you have time.
RE: Bull Family in La Plata Cemetery I am not a relative of the Bull family but knew some members of this family since several generations of my family & my husband's lived in the La Plata, Mo. area. I have been working on adding memorials, obits and photos for all burials in the La Plata cemetery since I have such a close connection to La Plata. Will be glad to add any info. and make family links to the memorials I have created if you would provide the info. Have a nice day, Farm Girl from MO.
RE: Samuel D Bull Family in Burns Cemetery Hi Jon, I am a Bull and have found the Samuel Bull -45368426- that is related to me as a 1st cousin 8x removed. In my search I found the other Bulls and I have not found a connection to them yet. Most of mine came from the Hartford,CT area and Capt Thomas Bull who came from England.
Are you related? I have met 4 cousins I did not know I had through Find A Grave.
RE: Abner Galpin correction Hi Jon, I don't recall seeing an actual flag marker / holder while I was there (a couple of years ago). Since he's in a National Cemetery, I would hope that flags do get placed on the soldiers graves by the staff, but you'd probably have to call them to confirm that.
Abner Galpin correction Hi Jim, Thank you for kindly sharing the information for Abner Galpin. I have made the corrections in the memorial. I have also requested the transfer of the second memorial and will make the deletion when it's transferred to me. I really appreciate your assistance.