Gold-inlaid Colt Model 1851 Navy Revolver (serial no. 20133), with Case and Accessories https://www.rawpixel.com/image/9186333/photo-image-paper-aesthetics-frameFree Image from public domain licenseGeorge Washington before the Battle of Trenton by John Trumbull https://www.rawpixel.com/image/9182851/image-1776-horse-paintings-public-domain-john-trumbullFree Image from public domain licensePortfolio Cover for a Collection of Caricatures and Satires, Anonymous, British, 19th century https://www.rawpixel.com/image/9331069/photo-image-paper-hand-artFree Image from public domain licenseTUKO-SEE-MATHLA. A SEMINOLE CHIEF., from History of the Indian Tribes of North America https://www.rawpixel.com/image/9066758/image-vintage-public-domain-gunFree Image from public domain licenseRobert Koch and Richard Pfeiffer working in a laboratory, investigating the plague in Bombay. Photograph attributed to… https://www.rawpixel.com/image/13999075/photo-image-face-person-hospitalFree Image from public domain license