I don't know if this information is about your relatives, but I looked in ANCESTRY.COM and in the Database of Missouri Census 1830-1870, I found two Edward Schullers:
1850Schuller, Edward Being 31st Dist Township, Franklin County, MO
1860Schuller, Edward South Point Township, Franklin County, MO
Then, I looked at FAMILYSEARCH.COM and found a Charles Eschman who married a Amelia Lenk on 5 May 1883 in Saint Louis, St. Louis, Missouri.I couldn't help but think that he could be related to Augusta Eschman Schuler.
At FAMILYSEARCH.COM, I also found an Edmond Schuler who married a Corine Elisa Nestler on 23 May 1857 in Strasbourg, Bas-Rhin, France.
At FAMILYSEARCH.COM, I input Augusta Eschman and the results were:
Augustina Eschmann, F, Christening 7 Jan 1863 in Sankt Sevatius Katholisch, Eisenschmitt, Rheinland, Pruessen.Her parents are Caroli Eschmann and Evae Blaeser.
AugusteEschmann, F, Birth 4 Aug 1862, Civil, Dattenfeld, Rheinland, Pruessen.Her parents are Friedrich Eschmann and Margaretha Koepe.
Auguste Agnes Eschelmann, F, Christening 14 Jul 1852, Dom, Berlin Stadt, Brandenburg, Preussen.Her parents are Friedrich Florentin Eschelmann and Dorothea Therese Mueller.
Auguste Therese Eschelmann, F, Christening 4 Jun 1851, Sankt Jakobi, Berlin Stadt, Brandenburg, Preussen.Her parents are Friedrich Wilhelm Eschelmann and Friederike Emilie Meyer.
Maybe some of this information will head you in the right direction.