Although the tombstone reads a birth year of 1778, it is believed that David was born much later than that date and his age was increasingly exaggerated as he grew older.

David is listed in a number of census records with the following estimated birth years from each: 1830 - age 30-40 (born bet 1790-1800); 1840 - age 40-50 (born bet. 1790-1800); 1850 - age 50 (born 1800); 1860 - age 64 (born 1796); 1870 - age 79 (born 1791). I've selective a birth year of 1796. None of these estimated birth years are close to the date of the tombstone. If he were born in 1778, he would have married a 16-year old Sarah Conkil in 1827 when he was nearly 50 years old and would have had children, first at age 49 and lastly at age 74. All of these are certainly possible, but a birth date of 1796 would have him marrying at age 31 and children between the ages of 31 and 56.

David was born to Michael Grubaugh (1752), the patriarch of the Grubaugh family, and Peggy. Not much information is known about Peggy, but she likely died sometime between 1806 and 1810. David married Sarah S. Conkil in 1827. She was born in 1811, so would have been only 16 years old. David and Sarah had 11 children, beginning with the first 5 being born in Ohio and the remaining children being born in Crawford County, IL. David and Sarah moved to Crawford County in about 1838. David is listed there in the 1840 census. David worked as a farmer.

Sometime between 1865 and 1870, David, Sarah and several of the children (some now married) moved to Christian County, MO. Moving with them were Katherine Ann Grubaugh Doran, Mary Jane Grubaugh, John Anderson Grubaugh, Sarah Lucinda Grubaugh and Martha Grubaugh. The family is listed in the 1870 U.S. Census and in the 1876 Christian County (MO) Agricultural census. See Sarah's memorial for a full listing of the children.

David had two grandsons. One was likely delivered to each of his two unmarried daughters (Mary Jane and Martha). The grandson were Herman B. "Hod" Grubaugh (b.22 Apr 1862) and Charles Marion Grubaugh (b.16 May 1869). Neither of these grandsons are listed in the 1870 or 1880 U.S. census listings, but both are mentioned in the 1876 Christian County Agricultural census.

David died in 1877 and Sarah died 9 years later in 1886. They would have celebrated their 50th wedding anniversary just prior to David's death.