1850 census of Hocking Co., Ohio, Falls township, enumerated 24 Aug, lists as family #576/584:
George Clark Sen, 31, farmer, b. Ohio; Elisabeth, 32, b. Pa; Amos, 10; Sarah, 8; Samuel, 7; Margaret, 5; George, 3; Mary, 1. All children born in Ohio.

1860 census of Hocking Co., Ohio, Falls township, Logan P.O., enumerated 14 June, lists on p. 53 as family #354/356:
George Clark Jr, 41, farmer, b. Ohio; Elizabeth, 42, b. Penn; Amos, 20; Sarah, 18; Samuel, 17; Margaret, 15; Mary, 11; Henry, 9; Lydia, 6; David, 4; John, 1. All children born in Ohio.

1870 census of Hocking Co., Ohio, Falls township, enumerated 21 July, lists on p. 76 as family #564:
Clark, George, 53, farmer, b. Ohio; Elisabeth, 53, b. Penn; Samuel, 27; Henry, 18; Lydia, 16; David, 12; John, 10; Mariah, 24; Emma C., 6, b. Ill; Elener, 4, b. Ill; Zelia, 1, b. Ill. Samuel through Mariah born in Ohio.

Mariah is the widow of George and Elizabeth’s son Amos.