Did Sampson N. Orr marry? You could try familysearch.org ..they have marriages to 1927. On marriage certificate you should find the name of his parents. Have you checked with the cemetery he is buried? If Sampson lived in Ohio, and died in Ohio than he might be buried in the same cemetery as his parents... if so you could go to the library and look for an obit. Have you looked for a birth certificate? On familysearch.org they have birth records to 1912. Keep in mind that these records are indexed and something you might find the spelling different due to the record and the spelling of the person who made the record, etc.
Does Sampson have silbings? If so have you looked for their birth record to see what parents are listed???

Best wishes in your search.

I have info that his parents may be Adam Orr or Adam N G Orr and Elizabeth. Adam N G Orr was born 1812 in Ohio and dob 11/28/1889, buried in Westboro Cemetary in Wilmington OH. My info shows Sampson was born un 1843 and dod 4/9/1866. No info on any marriages. Sampson was a private in Company G, organized at Wilmington, Clinton Co., OH. Mustered at Camp Dennison 7/15/1861. Mustered out of service 6/21/1864. But I also found info that says he was killed in the Civil War on 4/9/1866. He had three brothers, William H, Samuel Barney and Abraham D. I am trying to determine if Adam N G is his father and hope to find info before Adam. I will try familysearch.org to see if I can find any further info. Thanks for the tips.