Union forces under William T. Sherman enter the city of Meridian, Mississippi after a successful month of campaigning through the central part of the state. The capture of this important southern town, well known for its industry and storage capabilities, severely hampers the efforts of Confederate commanders to sustain their armies in the deep south, Georgia and west of the Mississippi River.
The CSS H.L. Hunley, a seven-man submergible craft, attacked the USS Houstonic outside of Charleston, South Carolina. Struck by the submarine's torpedo, the Housatonic broke apart and sank, taking all but five of her crew with her. Likewise, the Hunley was also lost and never heard from again until discovered in 1995 at the spot where it sank after the attack.
In Georgia, Camp Sumter Prison Camp opens. Universally referred to as Andersonville Prison Camp, it will become notorious for overcrowded conditions and a high death rate among its inmates.
Ulysses S. Grant is appointed lieutenant general, a rank revived at the request of President Lincoln. Grant assumes command of all Union Armies in the field the following day.
As part of an overall Union strategy to strike deep into various parts of the Confederacy, a combined force of army and navy commands under General Nathaniel Banks begins a campaign on the Red River in Louisiana.
Louisiana the first major battle of the Red River Campaign in Louisiana.
The Union Army under Banks defeats the attempt by Confederate forces under General Richard Taylor to drive them out of Louisiana. Unfortunately, the result of the campaign would be less than desired as it drew to a close in the first week of May with Confederates still in firm control of most of the state.
After a rapid raid through central and western Tennessee, Confederate cavalry under Nathan Bedford Forrest attacked and overwhelmed the Union garrison at Fort Pillow, located on the Mississippi River. Among those garrisoning the fort were African American troops, many of whom were murdered by Forrest's angered troopers after they had surrendered. The affair was investigated and though charges of an atrocity were denied by Confederate authorities, the events at Fort Pillow cast a pall over Forrest's reputation and remained an emotional issue throughout the remainder of the war and after.
The opening battle of the "Overland Campaign" or "Wilderness Campaign". General Ulysses S. Grant, accompanying the Army of the Potomac under General Meade, issued orders for the campaign to begin on May 3. Lee responded by attacking the Union column in the dense woods and underbrush of an area known as the Wilderness, west of Fredericksburg, Virginia.
With three Union armies under his command, General William T. Sherman marched south from Tennessee into Georgia against the Confederate Army of Tennessee under General Joseph Johnston, the objective being the city of Atlanta.
Lee successfully stalls Grant's drive toward Richmond.
Six miles north of Richmond, Confederate cavalry under General J.E.B. Stuart blocked a force of Union cavalry under General Philip Sheridan. General Stuart was mortally wounded during the encounter.
General Sherman's armies are blocked at Resaca by General Johnston's Army of Tennessee. After two days of maneuvering and intense fighting, Johnston withdraws. Sherman will advance but take precautions against ordering any further massed assaults where high casualties may occur.
Relentless and bloody Union attacks fail to dislodge Lee's army from its strong line of defensive works northeast of Richmond.