The Battle of Gettysburg, Pa., July 3rd, 1863, publisher Currier & Ives https://www.rawpixel.com/image/9183877/the-battle-gettysburg-pa-july-3rd-1863Free Image from public domain licenseBattle between the Monitor and Merrimac, Smithsonian National Museum of African Art https://www.rawpixel.com/image/8849239/battle-between-the-monitor-and-merrimacFree Image from public domain licenseWounded soldiers in hospital by Mathew Brady. Original public domain image from Flickr https://www.rawpixel.com/image/8799886/photo-image-vintage-public-domain-peopleFree Image from public domain licenseExcised Knee Joint. A Round Musket Ball in the Inner Condyle of the Right Femur [Gardiner Lewis, Company B, Nineteenth… https://www.rawpixel.com/image/9330759/photo-image-art-medicine-vintageFree Image from public domain licenseReturn of wounded Confederate prisoners, under a flag of truce, during the American Civil War. Wood engraving. https://www.rawpixel.com/image/13977326/image-person-medicine-artFree Image from public domain licenseFranco-Prussian War: Civil unrest in Paris. Wood engraving after W. Simpson. https://www.rawpixel.com/image/14019305/franco-prussian-war-civil-unrest-paris-wood-engraving-after-simpsonFree Image from public domain license