His death certificate records James Thomas McCormick, age 71 years 1 month 8 days, born 20 Dec 1869 in Montgomery Co., Kentucky, died 28 Jan 1941 in rural Fayette Co., Kentucky, residence Armstrong’s Mill Road, married, husband of Amanda Watts McCormick, age 68, farmer, father G. W. McCormick, born in Ky, mother’s maiden name Elizabeth Lewis, born in Montgomery Co., Ky, cause of death valvular heart disease, informant Roy McCormick, Lexington, Ky, burial in Mt. Sterling, Ky.

He does not appear with the family at all in the 1870 census, but he is recorded as age 11 in the 1880 census. So unless he was adopted, he was probably really born in Dec 1870.

1900 census of Montgomery Co., Ky, Spencer precinct, enumerated 5 June, lists on p. 4A as family #66/69:
McCormick, Thomas, 31, b. Dec 1868, farmer; Amanda M., wife, 27, b. Oct 1872, married 8 years, mother of 3 children, 3 living; Roy S., son, 7, b. Dec 1892; William, son, 4, b. Aug 1895; Geo R., son, 3, b. Apr 1897. All born Ky Ky Ky.

1910 census of Montgomery Co., Ky, Harts precinct, Mt. Sterling, enumerated , lists on p. 6B as family #136/142:
McCormick, Fred, 41, farmer; Amanda, wife, 36, first marriage for both, married 18 years, mother of 5 children, 5 living; Roy, son, 17; William, son, 14; Richard, son, 12; Glaydis, dau, 9; Thomas H., son, 6. All born Ky Ky Ky.

I do not know the explanation for Thomas reporting his name as Fred. (Both Thomas and Fred are also recorded with their father, see his notes.)

I cannot find this family in the 1920 census.

1930 census of Fayette Co., Ky, district 6, enumerated 4 April, lists on p. 3b as family #64/66:
McCormick, Joseph T., 61, age at first marriage 21, farmer; Amanda, wife, 57, age at first marriage 16; Thomas H., son, 26, single, farmer; George R., son, 32, single, laborer at nursery. All born Ky Ky Ky.