A global war in 1862-1867... I am not sure if the scenario is too fast or too slow.
Technology would be pretty much similar to 1860's technology OTL, including weapons and railroads. OTL, Molkte (the older) devised a war strategy based on massive trasnportation provided by trains, and that granted Prussian victory in seven weeks over Austria. This time the conflict occures 5 years earlier which might mean that Molkte's doctrine were not ready.