World History Maps Interactive Historical Atlas of the Civil War, detail page for:

Number One, CS Army Department May 27, 1861 - Jun 25, 1862

CS Dept. of Number One created included southern Louisiana southern Mississippi and southern Alabama, May 27, 1861
Daniel E. Twiggs Commander, May 27, 1861 - Oct 7, 1861
Southern Alabama detached from Dept. of Number One, Sep 12, 1861
Mansfield Lovell Commander, Oct 7, 1861 - Jun 20, 1862
Area around Pascagoula Bay Mississippi transferred from CS Dept. Number One to Dept. of Alabama and West Florida, Dec 12, 1861

Expedition to New Orleans, Mar 20, 1862 - May 1, 1862
Fort Jackson, battle, Apr 16, 1862 - Apr 24, 1862
New Orleans, US occupation, Apr 28, 1862 - May 1, 1862
CS Trans Mississippi Dept. created Arkansas transferred from Dept. Number Two Dept. of Texas discontinued and absorbed Dept. of The Indian Territory discontinued and absorbed western Louisiana transferred from Dept. Number One eastern Louisiana and Missis, May 26, 1862
Earl Van Dorn Commander to transfer forces, Jun 20, 1862 - Jun 25, 1862