- February 23, 1862
- July 20, 1865
- Battle of Fort Bisland
- Battle of Irish Bend
- Siege of Port Hudson
- Red River Campaign
- On February 23, 1862, the U.S. War Department issued General Orders No. 20, creating “A new military department, to be called the Department of the Gulf.”
- The Department of the Gulf consisted of “all of the coast of the Gulf of Mexico west of Pensacola harbor, and so much of the Gulf States as may be occupied by the forces under Major General B.F. Butler.”
- On March 20, 1862, Major General Benjamin Butler arrived at Ship Island, Mississippi, and issued General Orders No. 1 assuming command of the Department of the Gulf.
- As commander of Union troops in the Department of the Gulf, Major General Benjamin Butler assumed the role of military governor of New Orleans after his soldiers marched into the city on May 1, 1862.
- During Major General Benjamin Butler’s tenure as military governor of New Orleans the forces under his command, known as the Army of the Gulf, functioned primarily as an army of occupation.
- On November 9, 1862, Secretary of War Edwin Stanton issued General Order No. 184, replacing Butler with Major General Nathaniel P. Banks in command of the Department of the Gulf.
- When Major General Nathaniel P. Banks assumed control of the Department of the Gulf, the Army of the Gulf, it consisted of only the 19th Corps.
- In 1863 the Army of the Gulf participated in three major engagements, the Battle of Fort Bisland (April 12, 1863–April 13, 1863), the Battle of Irish Bend (April 14, 1863), the Siege of Port Hudson (May 22, 1863–July 9, 1863) — all Union victories.
- Beginning in August 1863, the 13th Army Corps was added to the Army of the Gulf.
- In February 1864, two divisions from the 16th Army Corps were added to the Army of the Gulf.
- On March 12, 1864, the Army of the Gulf embarked upon the Red River Campaign.
- The Red River Campaign was a Federal fiasco, perhaps the biggest of the war. In addition to casualty totals that topped 8,700 soldiers, the expedition siphoned men and material away from other operations, perhaps extending the war.
- The U.S. War Department issued General Orders No. 192, on May 7, 1864. placing the Department of the Gulf under the dominion of the newly created Division of West Mississippi, commanded by Major General Edward Canby.
- Following the Red River Campaign, many of the troops in the Army of the Gulf were dispersed.
- On June 11, 1864, the 13th Corps designation was discontinued and the troops were transferred to other commands.
- In July 1864, the 1st and 2nd Divisions of the 19th Corps were sent to Virginia to participate in the Shenandoah Valley Campaign of 1864.
- On August 3, U.S. Naval vessels put roughly 1,500 troops from the Army of the Gulf ashore near Mobile, Alabama. The soldiers from those units, which included the 96th Regiment, Ohio Volunteer Infantry, then participated in the siege and capture of Fort Gaines (August 3–8, 1864) and the siege of Fort Morgan (August 9-23).
- On November 7, the 16th and 19th Corps, Army of the Gulf, were discontinued.
- On November 25, 1864, the units of the old 19th Corps still in Louisiana were transferred to the Reserve Corps, Army of the Gulf.
- Two divisions of the 16th Corps traveled to Nashville in time to participate in the Franklin-Nashville Campaign.
- On February 18, 1865, the 13th and 16th Corps were reorganized within the Division of West Mississippi.
- Under the command of Major General Edward Canby reorganized 13th and 16th Corps participated in the siege and capture of Fort Spanish (March 27–April 8, 1865) and Fort Blakely (April 2-9, 1865), which eventually led to the occupation of Mobile, Alabama.
- The storming of Fort Blakely is often cited as the last major infantry action of the Civil War east of the Mississippi River.
- The 13th and 16th Corps were officially discontinued on July 20, 1865.