A Confederate sentry would challenge anyone approaching his post and the approaching person would answer the challenge with the countersign(A word or phrase) to show that he was a "Friendly". Texas Confederate forces always moved to meet any threatened invasion of Texas. At the beginning Of the Red River Campaign most were guarding the Texas Coast, when Shreveport and Northeast Teas were threatened, they moved in that direction. Morgan's Ferry was at what now is Melville La.