The Battle of Gettysburg occurred 150 years ago. This photo essay shows what it was like. It includes a photo of President Abraham Lincoln giving the Gettysburg Address. Photo credit: Alexander Gardner/Library of Congress

See the joy as students around the world graduate from their schools. More on education. Photo credit: Rahmatullah Nikzad/Associated Press

The Atlantic has compiled a photo essay about the issues that confront the US and Mexico. See the forty photos. More photography. Photo credit: AP Photo/U.S. Customs and Border Protection

Gun control, gun enthusiasts, politicians, and victims…all in this photo essay. More guns. Photo credit: Ben Garvin/The St. Paul Pioneer Press

CNN has compiled photos of Kim Jong Un and the North Korean military in this photo essay. More photography.