Robert Barnhill was the son of Samuel (1732 – 1794) and Jean (Craig) Barnhill (1734 – 1814). Samuel was the son of Robert Barnhill and Sarah Smith, Jean was the daughter of Daniel Craig and Margaret Bromfield.

Robert was born Feb. 28, 1769. Samuel and his family moved from Washington County, PA to Scott County Kentucky in 1789/1790.

Robert married Sarah Marvis, Feb. 8, 1791 and moved from Kentucky to Butler County, Ohio in 1805. On March 6, 1820 he and his family were in Marion County, IN. Their family was one of the first to settle in the area. Robert had applied for 10 - 80 acre tracts of the land opened up by the treaty between the Federal Government and the Indians of the area. There was an out break of the "plague" due to an extra heavy rainfall in the summer of 1821, and was spread by a house raising, with all of the men in the area assisting. Robert died on Sept. 9 and was buried with his son William and other plague victims in the "Plague Cemetery". This cemetery is said to have been about 150 feet southeast of Robert Barnhill's home at the time.

"HISTORY OF INDIANAPOLIS AND MARION COUNTY, INDIANA" BY B. R. SULGROVE, Page 649

"The family of Robert Barnhill and his wife consisted of twelve [13] children, viz. : Samuel, John, William, Daniel, Robert, James, Hugh, Jane, Katie, Sally, Nancy, and Mary, — who became Mrs. Speer, and mother of William H. Speer, one of the most prominent citizens of the township. [missing Margaret]
The widow of Robert Barnhill moved with her family (as before
stated) to Wayne township soon after the death of her husband, and in 1829 she was assessed on eighty acres of land in the township, described as the southeast quarter of section 22, township 16, range 2.
She married a second husband, Jacob Whitinger. Her sons, Robert and Hugh Barnhill, are now living near the north line of the county."

Robert's will was the first to be entered for probate in Marion County. The will was filed June 4, 1822, Indiana State Archives.