In feudal times, a hundred may have been a unit of land capable of fielding a hundred men-at-arms. When Great Britain first settled Delaware, a hundred was simply a subdivision of a county, much like a township. My earliest Simpson ancestor, John Simpson Sr., born about 1729, farmed in one of the early Delaware hundreds, the Mispillion Hundred of Kent County.
When John Sr. died about 1775, he left land for two of his sons, John Jr., my ancestor, and Robert Simpson. I can find both these men, farming close to each other, on the 1800 U.S. census. However, that census has another Simpson, named Thomas, farming in the Mispillion Hundred, right next door to John Jr. Who was this Simpson?
Some research on Ancestry.com quickly showed that Thomas Simpson was the son of Moses. On many Ancestry.com family trees, people have placed Moses as the brother of John Sr. and the son of William Simpson. This would make some sense with their sons farming right next to each other. John Jr. and Thomas inherited their farms from John Sr. and Moses, who would have also would have farmed right next to each other. It isn't much of a leap to imagine that John Sr. and Moses both inherited their farms from a common father.
However, there was no paper record that these two men were related. Worse, after reading the will of William Simpson, born about 1708, I found that he had left land and goods to Moses, who was also the executor of his will, and to three of his daughters, but did not even mention John.
So were John and Moses related? There was only one way to know for sure. I found a descendant of Moses, Lee Simpson, who was interested in genealogy and I asked him to take a Y-DNA test. Since Y-DNA does not recombine each generation, only mutating very slowly over centuries, Lee and I should have mostly identical Y-DNA.
And we do. John Sr. and Moses were certainly related. Given the lack of any other Simpsons in the area, it is probable that they were brothers. It turns out that these unsourced trees on Ancestry.com were right after all.