The Svalbard Global Seed Vault was opened on Feb. 26, 2008. Carved into the Arctic permafrost and filled with samples of the world's most important seeds, it's a Noah's Ark of food crops to be used in the event of a global catastrophe.
Army Sgt. 1st Class Joshua Gendron carries the remains of Army Sgt. Charles Schroeter, who was awarded the Medal of Honor for gallantry in an 1869 battle during the Indian Wars.
Protesters close their eyes in silent prayer as they stand on the South Carolina Statehouse steps during a rally to take down the Confederate flag, Saturday, June 20, 2015, in Columbia, S.C.
Rainier Ehrhardt/Associated Press
The ill-fated Sultana in Helena, Ark., just before it exploded on April 27, 1865, with about 2,500 people aboard. Most were Union soldiers, newly released from Confederate prison camps.
Library of Congress
1st Lt. Alonzo Cushing, shown in an undated photo provided by the Wisconsin Historical Society, is expected to get the nation's highest military decoration -- the Medal of Honor -- this summer, nearly 150 years after he died at the Battle of Gettysburg.
Wisconsin Historical Society/AP
Waverly Adcock, a sergeant and founder of the West Augusta Guard, prepares his company for inspection and battle at a Civil War re-enactment in Virginia. Sara Smith, whose great-great-grandfather was wounded at the Battle of Gettysburg, holds the Confederate battle flag.
Courtesy of Jesse Dukes