1860 census of Bath Co., Ky, Owingsville P.O., enumerated 11 July, lists on p. 110 as family #799:
William Johnson, 21; Catharine, 18.

The birthplace and occupation columns are blank on this entire page.

1870 census of Rowan Co., Ky, Pine Grove precinct, enumerated 24 June, lists on p. 8 as family #50:
Johnson, William, 32, farmer, b. Indiana; Catherine, 28; William, 9; Annie, 8; Ernest, 6; Josephine, 3; Hattie, 1. Doniphan, Mary, 17, domestic servant. All except William born in Kentucky.

1880 census of Menifee Co., Ky, Beaver precinct, enumerated 23 June, lists on p. 28 as family #163:
Johnson, William, 43, farmer; Catherine, 38, wife; William, 19, son; Mary, 17, dau; Earnestine, 15, dau; Viola, 13, dau; Charley, 10, son; John, 7, son; Cordely, 3, dau; Elbert, 1, son. Doneyhue, Althy, 18 (f), boarder. All born Ky Ky Ky.

The daughter Earnestine should be a son Earnest. Probably they gave his full name Ernest Aaron, and since Aaron is always pronounced with one syllable in Kentucky, like “Ern”, together they sounded like “Ernestern.”

1900 census of Rowan Co., Ky, Pearce precinct, enumerated 2 June, lists on p. 2A as family #21:
McKinney, Gaddice B., 21, b. Feb 1889, farmer; Gertrude C., wife, 15, b. June 1884, married 10/12; Johnson, Catherine G., boarder, 58, b. Mar 1842, widowed. All born Ky Ky Ky.

The relationship for Catherine should be mother-in-law.