I have seen a recurring mistake which has been posted and perpetuated in many of the trees which have Jesse Kirby of Warren County, Kentucky as an ancestor. I hope this message will correct that error. The common mistake has Jesse Kirby's youngest daughter Mary "Polly" Kirby marrying her own nephew, James Potter. There are in fact two women named Mary "Polly" Kirby who are connected to this tree. Jesse's daughter, Mary was born 26 February 1879 and was married to Samuel S. Kerby in Warren County, Kentucky on 23 February 1819. She then moves to Lafayette County, Missouri where she marries William Johnson on 6 July 1844. She is found living with William's son, Nimrod Johnson, on the 1850 census in Jackson County, Missouri. She subsequently moves to Plumas County, California and is residing there with her oldest son Alex Kerby in 1870. She dies in Plumas County, California on 7 October 1878.
A different lady, named Mary "Polly" Kirby was born 25 February 1809. She marries James Potter on 30 April 1825 Warren County, Kentucky. James Potter is the son of William Potter and Nancy Kirby (daughter of Jesse). Mary "Polly" Kirby and James move to McCracken County, Kentucky and raise 13 children all of whom have descendants in the McCracken County, area. Mary Polly Kirby Potter dies 10 January 1897. These are two different people who married different men. I hope this will be useful information for those people tracking these families and will eliminate some of the confusion regarding these women with identical names.