Amy, are you certain about Xavier's wife's name? Because I found a Xavier Arnold who married a Caroline Kuehn in St Louis, 1866, and a Xavier Arnold who married a Katharina (von) Arburg in St Charles, MO in 1852, plus a Xavier Arnold who married a Catherine Sessig in Calhoun in 1864. All are listed on the LDS website, Xavier could also be spelled Xaver.
I also downloaded some more information about the history of the Moses family in New England. If you are interested, let me know.