Dawn - See my posting to the "Bigsby" surname group where this question was first raised. Samuel Merrill Bixby was born in 1833 and I give references to him the National Cyclopedia of American Biography and the "Descendants of Joseph..." book.
The original poster had heard family tales that her ancestors founded the company, but the family names she gave (Amos Bixby perhaps born in NY in the 1820's) would suggest otherwise. There's no apparent link between the shoe company founder and Susan's ancestor.

- Jim Bigsby