Daniel Majook Gai from South Sudan goes in and out of his war-torn country to help children there go to school. Courtesy of Project Education South Sudan hide caption

itoggle caption Courtesy of Project Education South Sudan

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 hide caption

itoggle caption 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 hide caption

itoggle caption Courtesy of Jesse Dukes

A small group of 8- to 12-year-olds learn about how soldiers trained for the Civil War. Michael Tomsic/WFAE hide caption

itoggle caption Michael Tomsic/WFAE

How did the food taste? These faces say it all. Photograph from the main eastern theater of war, Meade in Virginia, August-November 1863. Timothy H. O'Sullivan/Library of Congress hide caption

itoggle caption Timothy H. O'Sullivan/Library of Congress

Activists in the town of Saraqib, Syria, hold a poster that reads, "Sheikh Moaz al Khatib represents me." Courtesy of Mahmoud Bakkour hide caption

itoggle caption Courtesy of Mahmoud Bakkour

Rosa, Charley and Rebecca are three of eight freed slaves who sat for portraits in 1863-1864 that were sold to raise money to fund schools for emancipated slaves in Louisiana. The three were chosen because it was believed their near-white complexions would draw more sympathy — and support — from a country torn apart by slavery and civil war. Charles Paxson/Library of Congress hide caption

itoggle caption Charles Paxson/Library of Congress