Thousands of Confederate troops unleash a surprise attack on Union camps at Shiloh Church near Pittsburg Landing on the Tennessee River on April 6, 1862.
The onslaught surprises Union Maj. Gen. Ulysses S. Grant and his tens of thousands of fighters massed there. But the federal forces rally and bitter fighting rages for hours as Confederates slowly gain ground. Despite the advantage of surprise, Confederate troops become disorganized before Grant's pummeled forces hunker behind defensive positions and fighting subsides at nightfall.
The next day, Grant goes on the attack. His Union forces totaling more than 54,000 troops, slam into Confederate ranks, eventually forcing their withdrawal and securing the Union a victory that further burnishes Grant's reputation as a general who fights and wins.
Elsewhere, Union Maj. Gen. George B. McClellan has sent out first forces of his vast army from Fort Monroe on the Virginia coast as he ramps up for his long-awaited Virginia peninsula campaign. Soon, those Union troops meet a small Confederate army at Yorktown, dug in behind the Warwick River. Confederate Maj. Gen. John B. Magruder uses theatrics -- including frequent marching back and forth of troops and loudly shouted orders -- to convincingly suggest he has a far bigger force than he actually has.
The Union forces are swayed by the Confederate show. McClellan suspends moves toward Richmond and orders siege fortifications built.
Heavy guns are brought up by Union forces and on April 16, Union forces testing the Confederate line, trigger a battle that leads to more than 300 casualties. McClellan hesitates to follow up, delaying two more weeks and Magruder's forces will ultimately slip away. But a major ground campaign long promised by McClellan is on.