Mecosta County Portraits and Biographical Sketches
"United States Census, 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MC1Q-WPQ : 12 April 2016), Virgil Seymour in household of Rodney Seymour, Redfield, Oswego, New York, United States; citing family 105, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).
"United States Census, 1880," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MZFM-BY9 : 8 September 2017), Virgil J Seymour, 1880; citing enumeration district ED 261, sheet 48D, NARA microfilm publication T9 (Washington D.C.: National Archives and Records Administration, n.d), roll 0915; FHL microfilm 1,254,915.
It may be possible to confirm family relationships with Virgil by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
Y-chromosome DNA test-takers in his direct paternal line on WikiTree:
Denny Seymour :
Family Tree DNA Y-DNA Test 111 markers, haplogroup R-BY3298, FTDNA kit #108347 +
Y-Chromosome Test 419 markers, haplogroup R-Y20344