Not all sources agree that Joseph and Nancy are children of John and Hannah, but it seems likely that, in 33 years of marriage, they would have had more than just four surviving children.

5.  Joseph THOMPSON, b. ca. 1774
6.  Nancy THOMPSON, m. 20 Aug 1815, Botetourt Co., VA, William WILLIAMS

Nancy's marriage date puts her a generation out of synch.  I doubt if she could be a daughter because if Hannah were married in 1755 and had children for 25 years, her children could be expected to marry ca. 20 years later, in other words ca. 1775 to 1800.  Nancy's marriage in 1815 makes it a real stretch — unless it was Nancy's second marriage.

In the 1850 Census, son William gives his birthplace as Pennsylvannia, which makes it extremely unlikely that either of his older brothers, Thomas or John, was born in Botetourt Co., VA, as is given by most secondary sources.  If John and Thomas were, in fact, born in Botetourt Co., VA, then I think there is little chance that this William — the one who married Temperance Brickey — is a son of John and Hannah (WALDRUM) THOMPSON.  THOMPSON is a very common surname, and it is extremely easy to mix up individuals, especially ones named John, James, or William.

1.  John Thompson of Botetourt County, Virginia [link died] by Frances Dumas.  In 1787, John Thompson paid his taxes on his land (135 acres adjoining that of Jarrett Brickey).  In 1788, Hannah sold this land signing the deed as a widow, along with three sons, Thomas, John, and William, presumably the only children of age at the time.  A few years later, a fourth son, James, appears on a quitclaim deed for the same land, so he has presumably come of age in the interim.

2.  Joe Thompson's Genealogy Database [link died] by Joe Thompson.

3.  Ancestry World Trees (online at Ancestry.com).

4.  LDS.  Family Search: Internet Genealogy Service: IGI - International Genealogical Index and AF - Ancestral File (online at FamilySearch.org).

5.  Broderbund.  World Family Trees.  Vol. 4, Pedigree No. 3745.