The Gravier family who married into the Noble family in Arkansas County, and later in Jefferson County (created partly from Arkansas County) were in the area much earlier than anyone who would have been coming over from France and serving in the Civil War. Ambrose Christian Gravier (also known as Grabert or Greber) was christened 18 April 1741 in Little Red Church, St. Charles Parish, Louisiana. He married Catherine Edelmer/Hedelmer (christened 8 May 1745, same church; died about 8 Jan 1793). One son was Francois Ambrose Gravier, and he married Suzanne Vannoy (perhaps Menoy). This couple's daughter, Frances Gravier/Greber married John Noble (Senior) in 1827 in Arkansas.

The name was changed over time from the German Greber/Grabert to Gravier because they were living in a heavily French area, but their community was very German in the beginning.

I've not run across any other Graviers in this area, but that doesn't mean anything really. When did your Benjamin Gravier first appear in Arkansas County, Arkansas, records? Do you have some ship's record or other info concerning his arrival in America? What type of funds were his parents coming to collect from "Louisiana purchase"?