Debi: I have a Barbara Elizabeth Oberst, born October 31, 1827 in Unterowisheim, Baden, Germany. I do not show her either dying or marrying so I assume she could have left for another villiage and then New York. Two of her four siblings did. I have no record of any Caspar Helfrich. The New York City Archives have very good naturalization records. You might want to look there.