I am able to update this family at last.This trio traveled to Wheeling, Ohio Co., West Virginia:
SCHWERTFEGER, Carl, age 63, Baker, from Sievershausen; EBBEGHAUSEN, Auguste, age 26, from Sievershausen; EBBEGHAUSEN, Mathilde, age 10 months, from Sievershausen. Ship "Johann Kepler" departed from Bremen and arrived in NY 28 October 1865.
Carl is apparently the father of Augusta, which fits with the family story.
Augusta must have been the widow of an Ebbinghausen (the above most probably being mistranscribed), and married John Groppe a year later 1866, where she had Louisa, CHristian, William, John, Emma (the girls married into Smith and Sonnenwald families).
Hope to find the name of Carl's wife, as well as other children in the family.