Archduke Ferdinand and his Duchess were assassinated while in their carriage. Archduke Ferdinand was heir to Austria Hungary's throne. It happened on June 28, 1914.
On this day, Austria-Hungary declared war on Serbia. That was exactly one month after Archduke and his Duchess were murdered. Other nations were dragged into the war due to thier alliances.
Germany angered the US when a German submarine sunk the Lusitania. The Lusitania was a British passenger ship. 1,000 people died including 128 US citizens. Afterwards, Germany promised not to attack anymore passenger ships.
.Between those days, Germany sank 5 US merchant ships. Afterwards, President Wilson felt there was no choice but to enter the war. Germany did to anger the US.
The US found a telegram that said Germany had asked Mexico to go against the US if the US entered the war. Then, Germany sunk 5 US merchant ships. President Wilson thought there was no choice but to enter the war.
The war was ended by the signing of a document called the Armistice. All fighting was to end at 11:00 am on that day. The war had lasted for 4 years. More than 110,000 soldiers died and millions more were wounded.