Mary's Notes:
1860 CENSUS, Colusa Twp, Colusa, CA: "Mary E.", 6 years, born WA Territory. Living with parents and 4 siblings. (Eileen DERR gives name as "Ellen".)
1880 CENSUS, Shoals Creek, Newton, MO: "Mary E.", 24 years, born IN, parents born OH. Living with spouse, Isaac N. WALKER, and son. Is she ours?

Holt Co, MO Marriages: Mary Ellen POTTER, daughter of William, and Isaac N. WALKER, 28 Jul 1868, page 256.

Mary Ellen is not listed as an heir in her father's Will, so presume she has died before 1888.

Isaac 's Notes:
Source: Holt Co Marriages, Book M, page 256.

1880 CENSUS, Shoals Creek, Newton, MO: 29 years, born KY, father born KY, mother born IL, miner. Living with wife, Mary E. and son, Charles A. (6 years, born KS). Are they ours?