Henry L. Abbot served in the Department of the Gulf under NP Banks. Several of his maps are in the OR Atlas. I found one, though, that is not and was inquiring if anyone knew the location. Its titled "Map No. 8 Atachafalya Basin" and shows the March-April 1863 invasion of Acadiana. I have contacted washington dc, where his papers are, and I am hoping for a reply in the next decade. Appreciate the help.