In his preface to his list of Civil War veterans buried in Middle Patent cemetery. Richard Lander stated that no military service was found for Brinkhoff, although his name was on an early list of veterans made by Arthur Hendry, charter member of the Armonk Legion Post 1097.
A GAR metal marker was on his grave according to the WPA card file. However, the WPA information is incorrect, the burial is not Brinkerhoff, but Brinkhoff - a foreign born who is not likely to have been a lieutenant in the 3rd New York Artillery Regiment. Records of the 3rd Artillery Regiment does not show either name as a member.
He died September 16, 1888 at age 51. He was born in 1837, making him about 24 at the beginning of the Civil War. He is not in the census of 1860 or 1870. He became a naturalized citizen on February 8, 1864 in Brooklyn, New York. There is no immigration record for him. The 1880 census shows him as a farmer living near Mead Road in Banksville, New York. He and his wife, Bertha, were both born in Bremen, Germany. He had four children, all American-born.
U.S. Naturalization Record Indexes, 1791-1992 (Indexed in World Archives Project)