GETTYSBURG: Here's how the Civil War's most important battle was fought

The three-day Battle of Gettysburg, the bloodiest battle of the Civil War, and one that tipped the scales in favor of the Union, ended 154 years ago today.

The Union fielded 90,000 troops in the battle, and the Confederacy 75,000, according to historian James McPherson. Eleven thousand died, 29,000 more were wounded and 10,000 were missing or captured.

The hallowed grounds of Gettysburg, as McPherson described them, witnessed nearly 10 times more casualties than the D-Day invasion.

There were many engagements over three days of combat - such as Devil's Den, the Slaughter Pen and Valley of Death - but some were more consequential to the battle, and therefore the war itself, than others.

Here's how the battle unfolded.