Complex sentence: Although confronted with strong competition from John Jacob Astor's American Fur Company monopoly, La Framboise ran a very successful business until 1818, when the American Fur Company convinced her to merge or sell out (accounts differ).
Split into simpler sentences: Although confronted with strong competition from John Jacob Astor's American Fur Company monopoly, La Framboise ran a very successful business until 1818. The American Fur Company convinced her to merge or sell out (accounts differ).