His WWI draft registration card, issued in 1917/1918 (the images on Ancestry do not show the side of the card that has the date it was filed), says John Milton McBrayer, age 45, residence Minor, Ky, born 24 Mar 1873, occupation farmer, self-employed, nearest relative Hattie McBrayer, wife.

1900 census of Rowan Co., Ky, Hoggtown precinct, lists as family #197:
McBrayer, John M., farmer, 27, b. Mar 1873, married 9 years; Annie, wife, 22, b. 1877, married 9 years; Charles H., son, 7, b. Jan 1893; Matt C., son, 5, b. Mar 1895; Hobart, son, 3, b. Jan 1897; Hiram, son, 1, b. May 1899; Day, Maudy B., 12, boarder, b. June 1887. All born Ky Ky Ky.

(Maudy Day was Annie’s sister, so she should have been listed as a sister-in-law.)

1910 census of Rowan Co., Ky, Hoggtown precinct, enumerated 30 May, lists on p. 13B as family #219/220:
McBrayer, John M., 37; Hattie, wife, 41; Charles H., son, 17; Mat C., son, 15; Hobert A., son, 13; Hiram, son, 11; Isaac, son, 8. All born Ky Ky Ky.

It is recorded as a first marriage for both, married 19 years, and Hattie is recorded as the mother of 4 children. That is inconsistent with other records, though, including the 1930 census, so I suspect that they had been married less than a year.

1920 census of Rowan Co., Ky, district #3, records as family #13:
J. M. McBrayer, 46; Hattie, 51; Isaac, 18. All born in Ky.

1930 census of Rowan Co., Ky, Hogtown precinct, enumerated 17 Apr, lists on p. 9B as family #157/160:
McBrayer, John M., farmer, 57, age at first marriage 17; Hattie L., 61, age at first marriage 40; Isac T., son, 27, age at first marriage 20; Ethel E., daughter in law, 25, age at first marriage 18; Paul V., son, 7. All born Ky Ky Ky.

Rowan Co. marriage book A, p. 34, records marriage of John M. McBrayer & Anna Day, on 27 Jan 1891. Bond in marriage book 2, page 94, contains consent notes from L. P. McBrayer, father of the groom, and Delphy Jane Day, mother of the bride. Bond surety by James Fannin.