How did the Union forces win the Battle of Shiloh?

The Union forces won the Battle of Shiloh through a combination of strategic positioning and effective leadership under General Ulysses S. Grant. Despite suffering initial setbacks from a surprise Confederate attack, Union troops utilized reinforcements and rallied on the second day of fighting. Key positions, such as the "Hornet's Nest," were held long enough to allow for a counteroffensive. The arrival of additional Union forces, particularly from General Buell's army, ultimately turned the tide in favor of the Union.