The display, which focuses on soldiers from Rotherham and Sheffield who fought in the Boer War, is taken from the collections of the York and Lancaster Regiment Museum.
The documents being displayed, which include photographs and written accounts, cover the period of the second Boer War of 1899 to 1902.
The York and Lancaster Regiment sent a full battalion of regular army soldiers, along with two half companies of volunteers, to help quell the Boer farmers’ rebellion.
Rotherham Council’s heritage services curator, Karl Noble, said: “Fighting in South Africa was a massive culture shock to the proud men of the York and Lancaster Regiment.
“The world they left in Rotherham, filled with giant steel mills, couldn’t have been more different to the rolling plains they arrived to, but they survived, adapted, and eventually helped to win the war.
“The collection really brings to life how the soldiers saw their new environment and you can’t help but get a sense of wonder and awe from them.”
The display runs until Christmas Eve at Rotherham Central Library.