The German states proclaimed their union as the German Empire under the Prussian king, Wilhelm I, uniting Germany as a nation-state. The Treaty of Frankfurt of 10 May 1871 gave Germany most of Alsace and some parts of Lorraine, which became the Imperial territory of Alsace-Lorraine (Reichsland Elsaß-Lothringen).The German conquest of France and the unification of Germany upset the European balance of power, that had existed since the Congress of Vienna in 1815 and Otto von Bismarck maintained great authority in international affairs for two decades. French determination to regain Alsace-Lorraine and fear of another Franco-German war, along with British apprehension about the balance of power, became factors in the causes of World War I. 

The Ems telegram had exactly the effect on French public opinion that Bismarck had intended. "This text produced the effect of a red flag on the Gallic bull", Bismarck later wrote. Gramont, the French foreign minister, declared that he felt "he had just received a slap". The leader of the monarchists in Parliament, Adolphe Thiers, spoke for moderation, arguing that France had won the diplomatic battle and there was no reason for war, but he was drowned out by cries that he was a traitor and a Prussian. Napoleon's new prime minister, Emile Ollivier, declared that France had done all that it could humanly and honorably do to prevent the war, and that he accepted the responsibility "with a light heart." A crowd of 15–20,000 people, carrying flags and patriotic banners, marched through the streets of Paris, demanding war. On 19 July 1870 a declaration of war was sent to the Prussian government. The southern German states immediately sided with Prussia.
Under which leader were German states united?
When was the Treaty of Frankfurt signed?
What did the Treaty give to Germany?
Who had those areas belonged to?
How did the British feel about Germany taking those areas?
Who was the French foreign minister at this time?
And who was the leader of the monarchists?
Did Thiers support war?
Did people in parliament support Thiers?
What did they call him?
Who was Napoleon's Prime Minister?
Was he bothered about supporting war?
How many people marched to support a war?
Where did they walk?
Were they empty-handed?
What did they carry?
Which war was all of this leading up to?
Did all of this have implications for the rest of the world?
Prussian king, Wilhelm I
under the Prussian king, Wilhelm I, uniting Germany as a nation-state.
10 May 1871
The Treaty of Frankfurt of 10 May 1871 
most of Alsace and some parts of Lorraine
The Treaty of Frankfurt of 10 May 1871 gave Germany most of Alsace and some parts of Lorraine,
France
French determination to regain Alsace-Lorraine and fear of another Franco-German war
apprehensive
along with British apprehension about the balance of power, 
Gramont
Gramont, the French foreign minister,
Adolphe Thiers
he leader of the monarchists in Parliament, Adolphe Thiers,
no
The leader of the monarchists in Parliament, Adolphe Thiers, spoke for moderation, arguing that France had won the diplomatic battle and there was no reason for war,
no
but he was drowned out by cries that he was a traitor and a Prussian. 
a traitor and a Prussian
but he was drowned out by cries that he was a traitor and a Prussian.
Emile Ollivier
 Napoleon's new prime minister, Emile Ollivier,
no
. Napoleon's new prime minister, Emile Ollivier, declared that France had done all that it could humanly and honorably do to prevent the war, and that he accepted the responsibility "with a light heart." 
15–20,000 people
 A crowd of 15–20,000 people, carrying flags and patriotic banners, marched through the streets of Paris, demanding war.
through the streets of Paris
A crowd of 15–20,000 people, carrying flags and patriotic banners, marched through the streets of Paris, demanding war. 
no
 A crowd of 15–20,000 people, carrying flags and patriotic banners, marched through the streets of Paris, demanding war.
flags and patriotic banners
A crowd of 15–20,000 people, carrying flags and patriotic banners,
a war with Prussia
On 19 July 1870 a declaration of war was sent to the Prussian government.
yes
French determination to regain Alsace-Lorraine and fear of another Franco-German war, along with British apprehension about the balance of power, became factors in the causes of World War I. 