On July 19th, 1870, France mobilised their army after declaring war on Prussia. After an initial Prussian incursion into Alsace, stiff French resistance forced the Prussian army to retreat back into Germany. The French troops, led by Marshal MacMahan (due to Napoleon III being ill and unable to lead the campaign*) pursued the Prussians to the Rhineland. Here they started their offensive and began moving towards Saarbrücken and Trier at first, with their ultimate goal being Koblenz, Mainz and Frankfurt. The French achieved victory after victory, though not as decisive as Napoleon III had hoped. Eventually, Denmark joined the war on the French side with the promise of regaining Schleswig from the Prussians. This event, along with separate treaties negotiated with the South German states allowing them a sort of status quo ante bellum peace, cemented the Prussian failure to win the war.
The peace treaty that was signed rearranged the political map of Europe. More specifically, Prussia was reduced in size while France and Denmark annexed some territory and set up buffer states.
This new rearrangement left France as the dominant power on the continent, and a few years after the war they hosted a conference to solve the Belgian Crisis. After months of tense negotiations a treaty was signed that allowed France to annex Wallonia. Flanders was reattached to the Netherlands and the Belgian king was put on the throne of the former Rhenish Republic, now Rhenish Kingdom.
To keep the pace with Britain the French departments were grouped into regions largely based on the historical provinces. Each region was responsible for the railway inside of its borders. This also made the French railway network more equalised regionally instead of being completely based on Paris. By the late 19th century the French had one of the densest railway networks in the world.
Finished on 10th November, 2012