As to tactics, I have a book on the Franco-Prussian war (I don't recall the author) in which he illustrates that the French were still fighting in a Napoleonic large lines of men whereas the Germans had begun using platoon tactics. From the vantage of the French, the German assault looked chaotic with small groups of men attacking willy-nilly. But for the Germans (who also had 80% literacy rates due to their great public school system- French literacy was 20%) each unit knew the goal and target of the attack and the platoons did what they needed to do autonomously without having to have direction from above.

US civil war General Philip Sheridan went to the war as an observer with German troops. To quote one website "“I found a great deal to interest and instruct me,” he commented, “yet nowadays war is pretty much the same everywhere, and this one offered no marked exception to my previous experiences.” The Prussian and German mobilization, execution on campaign, and overall discipline impressed him greatly, while Sheridan noted the “stupendous errors” of French strategy."

I often wonder if the German military organization of platoons was introduced to the US army based on Sheridan's observations given that we were only five years out of our civil war with its own napoleonic tactics.