It is my understanding that the 7th and 3rd Mississippi units were orginally formed to be part of the defense for the Mississippi/Louisiana coastal defense. However that was not to be since both units were soon called away to the Kentucky and Tennesse campaigns, leaving the Gulf Coast nearly completely undefended. Ship Island was given up without any real fight, that opened the door to Lake Ponchatrain to the north of New Orleans. The Confederate Navy could not hold the Mississippi river with the underpowered ships they had in service, leaving New Orleans an easy prize.
I believe one of the first amphib landings in took place at Bay St. Loius where a Union detachment, from Ship Island,caught a small group of the 3rd Miss. by surprise and ran them out of camp. This was while the 7th and 3rd were still in boot camp here. So yes, the Mississippi Gulf Coast and New Orleans was given up without a real fight. The 7th and 3rd Mississippi went on to glorly at places like Corinth, Shiloh, Chickamauga, Atlanta and Franklin and Nashville.
Could be I really have no idea since it is almost impossible fior me to take the Purvuis line back past 1850 census of Marion Co. Mississippi. I think you have Pitts and Pittman confused, I am related to the Pittman line. No problem sincea lot of folks make the same mistake.
Is this the book by Terasa Arnold & husband Terry Schriber (sp) of Louisiana?