Sir
Morgan's Ferry was based on the west bank of the Atchafalaya River in St. Landry Parish, on the "Old State Road," about 1.5 to 1.8 miles NNW of the town of Melville, and about 0.5 miles south of where Bayou Rouge debouches into the Atchafalaya. The location is shown on a map in the National Archives,purportedly a captured Confederate map.
NARA, Record Group 77, Map Z33-77, Eastern St. Landry Parish (NSU-LA #1399).
I obtained a copy of the map at the Cammie G. Henry Research Center, Watson Library Archives, Northwestern State University of Louisiana at Natchitoches.
Hope this answers your question.
Don Parker