Original: Designed by Heinrich Strack after 1864 to commemorate the Prussian victory in the Danish-Prussian War, by the time it was inaugurated on 2 September 1873, Prussia had also defeated Austria in the Austro-Prussian War (1866) and France in the Franco-Prussian War (1870 71), giving the statue a new purpose.
Simplified: By the time it was finished on 2 September 1873 Prussia had also beat Austria in the Austro-Prussian War (1866) and France in the Franco-Prussian War (1870/1871).