She likely traveled with her sister, Anna Maria Backman. They crossed the ocean in 1865 on board the ship B.S. Kimball, as recorded on the ship register. In 1870 census records, Augusta is listed as living in the household of Gustof Hider. Her given name is written "Charlotte." Anna is located on 1880 census records in the household of H. B. Hanson.
Her given name is "Charlotte" on the ship manifest.
Further research is needed to determine which company they traveled with.