Individual Details

Barnett Holtsclaw married Julia Ann Osborne, 14 Dec 1843, Greene Co, IN. Indiana Marriages 1802-1892, Ancestry. com.
The unplaced Zachary T. Holtzclaw, age 4, in 1850, was surely his orphaned child. Barnett doesn't appear in subsequent censuses.

Julia A. Holtsclaw married William McKee, 15 Oct 1858, which explains why this child was living in that household.

In 1850, in Greene Co, there was a 4-year-old, Zachry T. Holesclaw living with the family of William McKee, Hh 588. He wasn't with them in 1860, nor did I find him anywhere. But in 1870, he was again living in Greene Co, now married.
1870 Census. Richland Twp, Bloomfield P.O. Greene Co, Hh 39
Z. T. Holtzclaw, 23, shoe merchant, b. IN
Maria E., 21. John B. age one month.

Buried Faucett-Fellows Cemetery, Greene Co IN:
Maria E. Holtsclaw, born 11 Oct 1853, died 7 Oct 1870, wife of Z. T. Holtsclaw.

In 1880, the child John was living in Worthington Twp, Greene Co, Hh 250
Silesia Fossett, female, age 53, b. Ohio, father born MA, mother b. VT
Frank Fellows, age 22, son, b. IN. Edward Fellows, age 20, son, b. IN
John Holtsclaw, age 10, grandson, b. IN
Irene Haywood, age 39, servant, b. IN, parents b. TN

Death

Bef Oct 1858

Greene County, Indiana

Father	Martin Holtzclaw (1794 - 1870)
Mother	Sally Parsons ( - 1840)
Sibling	Beverley Holtzclaw ( - )
Sibling	Benjamin Holtzclaw (1817 - 1900)
Sibling	Hosea Holtzclaw ( - )
Sibling	Mary "Polly" Holtzclaw (1821 - )
Sibling	Martin Holtzclaw Jr. (1823 - 1894)
Sibling	Jordan Holtzclaw (1825 - )
Sibling	William Holtzclaw (1826 - 1911)