The claim of descent from the Signer appears to have originated with Warren Green Hooper during his political campaigning and apparently was not so claimed or even known of by his siblings or their offspring until long after the massive publicity after Sen. Hooper was murdered.

He was not closely related to the Signer. The authors of the book "Three Bullets Sealed His Lips," repeated but apparently never tested the claim of his ancestry - specifically, I find no authority in their bibliography other than newspaper articles based solely on Warren Green Hooper's own unsubstantiated claims made during his political life.

Warren G. Hooper's ancestry is as follows:
Warren G. Hooper b. 1904 California
son of J. Lewis Hooper b. about 1892 CA
grandson of John Lewis Hooper b. 1859 OH
great-grandson of Jacob Hooper b. 1817 OH
gr-great-grandson of Rev. James Hooper, b. 1789/90 MD
gr-gr-great-grandson of Jacob Hooper of MD and OH.

That oldest Jacob Hooper is listed on the 1790 Patapsco Lower Hundred census of Baltimore County, MD. He is found on a 1776 Maryland muster list and served during the American Revolution. His birthplace is disputed, but a vanity biography of another descendant was published in 1918 and said old Jacob was one of three brothers who came from Wales to Maryland around 1760.