Perhaps Joseph Landon of Bristol was his son. He was a brother of David Landon. First of all, I was interested in Publishing dates. I wanted to see what published material was available to the next author of any published work.
Authors tend to feed on each other.
And after 70 or more years, that record may no longer exist. Akerly, a Landon descendant. Judge Edward R. Landon's eulogy for Judge Smith. The following all mention Landons, but I haven't yet gone back to find the dates, etc. Some names had a list of 6 or more sources.