The oldest Kilgour I have researched is James Kilgour who was married to Isabelle Steele. He was born in Balbeggie, Fife, Scotland. They had at least two sons, James and William.
James used the spelling Kilgore. He was born in Donagheady, Down, Ireland. He married Margaret Low. They had at least one son, John Kilgore.
John Kilgore was also born in Donadheady, Ireland. He was married to Elpeth Howeson. They were married on July 9, 1713 in Fife, Scotland. John and Elpeth came to America. John died May 7, 1731 in Chester, Pennsylvania. They had at least two children: Robert & Jonathan.
Robert Kilgore was born in 1715 in Ireland. He married Margaret Spencer. He died in North Carolina. They had at least three children: Robert, Elizabeth and William.
Robert married Winifred "Milly Clayton. He fought in the Revolutionary War and was at the battle of King's Mountain. Robert died on December 31st, 1782 and died as a result of an Indian attack in Wise County, Virginia. Robert and Winny had at least five sons: Ralph, Robert "Robin", Hiram, Charles and William.
Ralph married Nancy Gray in Russell County, Virginia. They had at least three children: Ralph "Rafe", Sarah and John.
Rafe married Amelia "Milly" Wheatley. They had 10 children: Nancy Ann, Elizabeth, Sena, Nelson, Susannah, Esther Jane, Johnston, George, Mary "Polly", and Ira H.
Nancy Ann Kilgore married William "Billy" Addington. They had 14 children: Sarah, Mary, Amelia, Thomas, Margaret, Elizabeth, Josephine, Malinda, Harriet, Franklin, Millard, Eliza Jane, Laura and James.
Malinda Addington married John Martin Bentley. They were the parents of Otho Bentley.
Now remember back to John Kilgore who married Elpeth Howeson. They had at least two sons, my direct grandfather Robert and his brother, Jonathan Kilgore.
Jonathan married Elizabeth Jack. They had a son named Samuel Kilgore.
Samuel was born in Greenville, South Carolina. He married Elizabeth Scott. They moved to Mississippi. They had at least one son, James.
James moved from Mississippi to Hardin County, Texas. He married Elizabeth Sims. They had three daughters: Mary, Lydia and Francis.
Mary married William T Castle. They had two sons, George B. and Orville Frank.
George married a Georgia. They had 8 children: Rosa Lee, Carl, Qual Frank, James, Elizabeth, Sarah, Thomas and Charles.
Rosa Lee Castle married Lester Clarence Ryland. They moved from Texas to Arkansas. They had a daughter named, Betty Jo. They moved to Ohio.
Betty married Ivan R. Ely. They had a son named Eric.
Eric married Barbara Peters. They had a daughter named Erika Ely. She married Jason Douglas Mullins.
And that is how my son married his eighth cousin one time removed.