26 February – German company Commerzbank is founded in Hamburg.
10 March – The Deutsche Bank is granted a banking licence by the Prussian government.
16 July – In response to Bismarck's refusal to cede parts of the Rhineland to Emperor Napoleon III of France,[1] the near succession of a Hohenzollern to the Spanish throne, and the Ems telegram,[2] France declares war on Prussia, beginning the Franco-Prussian War.
4 August – Battle of Wissembourg: The first battle of the Franco-Prussian War begins when three Prussian-led German army corps surprise and get the better of the small French garrison of Wissembourg. Despite being heavily outnumbered, the French defenders fiercely resist and inflict three times their number in casualties.[3]