The attack — directed General James Longstreet, page though commonly known as Pickett’s charge after one of the participating corps commanders — was to be preceded by an artillery bombardment and accompanied by a flanking maneuver by Confederate cavalry.
Both these supporting efforts fell well short of the mark. The cannon fire failed to make any appreciable impact against the Union defenses, and the cavalry assault was deflected by a force of Union troopers (including an impetuous young officer by the name of Custer). In addion, logistical confusion led the Confederate high command to commit a number of already fatigued and under-strength units to the main assault…
…which was conducted across open ground in the face of massed artillery and rifle fire.
The remants of the Confederate thrust slammed up against “the Angle,” a salient created by a bend in the low stone wall the Union forces were using as cover.
Though the Confederates managed to break through the lines, their success was momentary. Instead of routing as expected, the Union forces fell back to a small copse of trees from which they staged a successful counterattack against the tattered remnants of the Confederate vanguard.
Having gambled — and lost — on this audacious and ill-conceived attack, Lee’s army was forced to abandon its invasion of the North and retreat back across the flood-swollen Potomac. Though the Union Army of the Potomac failed to capitalize on their victory by destroying the Confederate forces in detail, the Army of Northern Virginia was dealt a severe blow from which it was never able to recover.