Fought over the first three days of July 1863, the Battle of Gettysburg in Pennsylvania was one of the most crucial battles of the Civil War. On those hills and fields, over 160,000 soldiers struggled to survive. Preserved as Gettysburg National Military Park, visitors can hear their stories and walk in their footsteps. Sunset photo by Doug Shearer. Posted on Tumblr by the US Department of the Interior, 7/1/15.