Why was the outcome of the Franco-Prussian war important to Germany?

Answer 1

It was important, because Prussia(Germany) took French lands, and made the French determined to get revenge, leading to their big demands during World War I.

This war was oddly started, because Chancellor Otto Von Bismarck changed a letter the Kaiser was giving to a French ambassador he couldn't meet with to make it look insulting, and then France went to war with Germany over a letter!

It was important also for following reasons:

1. It led to the creation of the German Empire, under the leadership of King of Prussia who became Emperor which means the union of all the more or less little German States in a united great State. That was the realization of the Chancellor Otto von Bismarck's political project on which he had worked for about twenty years.

   That achievement wouldn't have been possible without the annihilation of the Austrian Empire's influence in Germany, reached in the 1866 and that, although temporary, of lowering France as Great European Power, reached in the 1870, both by means of a war.

2. The start of the economic and political "rivalry" soon spreading also outside Europe, between Germany and Great Britain which was then one of the grounds of the WW1.
3. The war lead Northern Germany and Southern Germany to join together into one nation. The war also made Alsace-Lorraine to be part of Germany. Germany also and occupation army in Paris until France paid up 5 billion francs in war indemnity

Answer 2

It was later the reason that Frace were on the allies side during World War l, against Germany. They were still angry, and influenced France's opinion of Germany's punishment in the Treaty of Versailles.