Why were the Germans able to so quickly sweep into France in 1870 but have such a difficult time in 1914?
Because Sedan and the Marne.
>>1190579
Machineguns and artillery
>>1190593
Mons Marne Meuse
I'm not quite sure I understand your question.
They "sweeped into France" slightly faster in 1914 than in 1870. It took a just over a month for them to reach the Marne (and be stopped there) in WW1.
In 1870, it took them about two weeks longer than that before they had broken through from the border clashes (at Sedan, where they incidentally won the war).
>>1190579
France had batter railways in 1914 which means they could bring reserves more quickly to the front line.
Other reason was that von Schlieffen plan was outdated and flawed.
>>1190579
Warfare changed.
