Overview
The Overland Campaign refers to the period from May 4 to June 24, 1864 in Virginia during the American Civil War. The Union Army of the Potomac repeatedly attempted to outmaneuver the Confederate Army of Northern Virginia and get between the ANV and Richmond (the Confederate capital), leading to a series of bloody battles. George Meade remained in command of the AotP, but general-in-chief Ulysses Grant accompanied the army. Robert E. Lee commanded the ANV. The campaign also includes several battles between Union and Confederate cavalry.
Major Battles
Wilderness (May 5-7, 1864)
Spotsylvania Court House (May 8–21)
Yellow Tavern (May 11)
North Anna (May 23–26)
Cold Harbor (May 31-June 12)
Trevilian Station (June 11–12)
Casualties
James Longstreet - accidentally wounded by his own troops (Wilderness).
JEB Stuart - killed in cavalry combat (Yellow Tavern)
John Sedgwick - killed by a sniper (Spotsylvania)
"They couldn't hit an elephant at this distance."
The number of casualties suffered by both sides of the campaign are some of the most debated of the Civil War and the source for most accusations that Grant was a heartless butcher. Estimates are 38,000-65,000 USA and 30,000-40,000 CSA. A recent book "Lee's Army During the Overland Campaign: A Numerical Study" by Alfred Young argues the Confederate army was larger and suffered more casualties than has previously been believed.
Aftermath
The Army of the Potomac began crossing the James River on June 15th, soon joining the assaults on and siege of Petersburg that would last until March 1865.
Further Reading
"Bloody Roads South: The Wilderness to Cold Harbor, May-June 1864" by Noah Andre Trudeau
Gordon Rhea's Overland Campaign Series: "The Battle of the Wilderness", "The Battles for Spotsylvania Court House and the Road to Yellow Tavern", "To the North Anna River", and "Cold Harbor"