Having a subscription to ancestry.com is a wonderful thing. I was looking for Artemas Lowell in the 1850 Federal Census in Marlow, Cheshire County, New Hampshire, but I didn't find him. He married Ellen Knapp, sister of Orlando James Knapp, Knapper's 2nd great-grandfather. Ellen Knapp is not to be confused with Charlotte Ellen Knapp, another of O.J.'s sisters. The hard copy genealogy I have states that Ellen married Aretmas Lowell on the 6th of March, 1851. I believe she met him in New Hampshire because she can be found in Stoddard, New Hampshire in the 1850 Census staying with a couple with the last name of Phelps, which I believe were cousins of her mother, Margaret Chase Knapp, who was born in Stoddard. There is some type of family connection there because Margaret and Isaac Palmer (Knapper's 3rd great-grandfather) named one of their sons Edward Phelps Knapp.
The genealogy also says that Ellen had two sons: Olcott Willis Lowell (who it says is from her first marriage), and George Lowell. Since I have found Ellen's birth year to be 1827 (from her memorial on Find-A-Grave and the 1850 census), and Olcott's birth year was 1851, I tend to disbelieve that Ellen was married before she married Artemas Lowell. The 1850 Census doesn't show her anywhere except with a couple named Edward and Eunice Phelps in Stoddard.
Ellen died in 1854, a year after delivering her son, George Lowell. She's buried in Joslin Cemetery in Stoddard. While looking for Artemas in 1850 in Marlow, I stumbled upon a Nathaniel and Lucy A Adams. This was intriguing because in the 1860 Census Artemas is shown married to a Lucy A Lowell, with children Frank and Lyman Lowell. Frank is 8 and Lyman is 7. I later found a Lyman Adams with the family in a later census. So when I saw Lucy A and Nathaniel Adams in Marlow, New Hampshire in 1850, my spidey-senses started tingling.
I plugged Lucy in as the 2nd wife of Artemas Lowell and found confirmation that she died as Lucy A Lowell in Marlow, New Hampshire in 1895. Is it proof positive that Lucy Ann Harrington Adams Lowell was Artemas' 2nd wife? No. But it's a strong circumstantial connection, and I believe it's correct. Artemas himself is shown to have died in 1898.