One of the concepts that followed from the defeat of Napoleon in 1815 was the beginning of a new movement called nationalism that shaped most of Europe in the years that followed, which also fanned the flames in Denmark and the German Confederation. In early 1848 Denmark included the Duchy of Schleswig, and the king of Denmark ruled the duchies of Holstein and Saxe-Lauenburg within the German Confederation. The majority of the ethnic Germans in Denmark lived in these areas with Germans making up a third of the country’s population, and the three duchies accounted for half of Denmark’s economy. There is a good Wikipedia article giving a full history of the Three Years’ War, or also known as the First Schleswig War (1848 – 1851) which was the first round of military conflict in southern Denmark and Northern Germany. The Schleswig-Holstein rebels used the Prussian Model 1849 rifled muskets, and these captured rifles were modified at the Kornberg Armory and issued to the Danish Army as the Model 1854. With muzzle-loading technology becoming obsolete, these rifles were converted to the Snider breech-loading system by the Copenhagen Armory and redesignated the Model 1854/65.