De Bienville warned away English traders and posted markers claiming the territory .
Between June 15 and November 10 , 1749 , an expedition headed by Celeron de Bienville , a French officer , traveled down the Allegheny and Ohio to bolster the French claim to the region .
officer   warned away English traders and posted markers claiming the territory .
Between June 15 and November 10 , 1749 , an expedition headed by Celeron de Bienville , a French officer , traveled down the Allegheny and Ohio to bolster the French claim to the region .