I've noticed that many careless researchers think that any man named John Newcomb is John Bearse Newcomb. This error is often combined with other incorrect information. I wonder sometimes if these people are really so careless, or if some are just deliberately lying to create confusion.
JBN, as many of us call him, was the author of A Genealogical Memoir of the Newcomb Family, published in 1874. He was born in 1824, the son of Obadiah Newcomb (1798-1840) and Molly Bearse (1795-1840). JBN married Arethusa Gould in 1850. Their son Andrew died the day he was born, and their daughter Foneta died unmarried at age 22. JBN has no descendants!
JBN's goal was to document every Newcomb in America. He couldn't do it. His work was amazing, but without access to the resources we have today, he missed a lot of people (as we still do), and occasionally made errors in identification. Nevertheless, his book is the best starting point for Newcomb researchers.
In 1923, JBN's distant cousin, Bethuel Merritt Newcomb (BMN), published an update to the genealogy, Andrew Newcomb and His Descendants. As the title indicates, BMN wasn't looking for every possible Newcomb, just the descendants of his own ancestor, Captain Andrew Newcomb. BMN was able to bring the work into the 20th century.