Actually, you should have read the whole article as it disproves the relationship between the Virgnia Simpsons and Grant.
From the blog
"However, Mr. Lane’s knowledge of Thomas’s ancestry is flawed in another significant aspect. He claims that Thomas Simpson had a brother, John, who was the maternal grandfather of President Ulysses Simpson Grant. If this were true, the parents of Thomas and John were John Simpson, born in Northern Ireland about 1738, and his wife, Hannah Roberts. This John did, in fact, emigrate as a youngster but fromNorthern Ireland; not Scotland. No evidence has been found to substantiate the claim that John and Hannah had a son named Thomas. Therefore, the claim that Thomas was of Scottish origin is suspect and probably a convoluted conclusion based on the belief that Thomas’s brother was President Grant’s grandfather."