Causes of WW1

Causes:
a) Militarism: militarism is the belief that a country should be militarily strong.  There is usually a strong tradition of military members in most families of the country.  The military is an honorable thing, and involvement is strongly encouraged for young adults.  It is also the belief that the country can and should use the military to protect itself and promote national interests.
b) Alliances: There were many alliances made throughout Europe that pulled almost every country into the war.  Serbia and Austria went into conflict, and all the alliances were put into effect.
c) Imperialism: This was also a motivator in the cause of the war because the victory pot included some very resource rich colonies.  Gaining control over these colonies would help the countries economy greatly and help in their international affairs.  Other countries would see that they have power and should be respected as a country.
d) Nationalism: Nationalism is the belief that a residents country is the best in the world.  This lead to all the European countries believing that they could not be defeated in a war.  The press also had a big hand in nationalism.  They began publishing  stuff that fueled nationalism.  Eventually this developed into the thoughts that their government was right, and that they could not be defeated in a war.  Europe was now a powder keg that was just waiting for one spark to set it off.

Spark of War: Austro-Hungarian Archduke Franz Ferdinand was assassinated by a Serbian terrorist by the name of Gavrilo Princip.  Th Serbians were mad that Austria-Hungary would not let the slavic provinces join with Serbia.  The terrorists then decided to assassinate the Archduke.  The Serbian military officers stood by the terrorists actions, prompting an ultimatum from the Austro-Hungarian government.  The Serbian government then rejected the ultimatum, causing Austria-Hungary to declare war on Serbia, starting the First World War.

Other:
a) Unrestricted Submarine Warfare (1915): Unrestricted Submarine Warfare was a military strategy instituted by the Germans during WW1.  The Germans promised to sink any armed ships in the Atlantic Ocean, but spare passenger ships.
b) Lusitania (sunk May 7, 1915): The RMS Lusitania was a passenger ship that was sunk by German U-Boats during the First World War.  This event prompted the USA to seriously consider entering the war on the side of the Entente.  A second explosion on the Lusitania would suggest that it was not only a passenger ship, but also a sneaky way for the Entente to carry weapons across the Atlantic.
c) Sussex Pledge (May 4th, 1916): The Sussex Pledge was made after  the French ship Sussex was sunk by German U-Boats.  This caused Germany to change its naval policies fearing that the US would enter the war.
d) Zimmermann Telegram (January 16, 1917): The Zimmermann Telegram was a note from German Foreign Secretary Arthur Zimmermann to Mexico.  The note was intended for Mexico, but was intercepted by British Intelligence.  The note asked that Mexico join the Central Powers in the case that the USA joined on the side of the Entente.  The note enraged the American public, and was a major cause in the USA joining the war in April.  Mexico never joined the war.

Sedition Act of 1918

The Sedition Act of 1918 expanded the offenses that were punishable by the Espionage Act of 1917.  These Acts were passed to keep the war effort cast in a positive light.  If the war were to suddenly be seen as a bad thing by the American people, it would prove to be disastrous.  The American people would begin to protest the war, and the government would have almost no choice but to pull out of the war.  Pulling out of the war would then damage international relations with the USA's allies in the war.  Having the American people buy into the war effort and support it was a must for the American government.

The Sedition Act broadened the ranges of offenses listed in the Espionage Act.  It banned the language that was "disloyal, profane, scurrilous, or abusive language" about the armed forces, the flag and the government and its institutions with contempt.  If you were convicted under the Sedition Act, you could face between 5 and 20 years in jail, depending of the severity of the offense.  The Sedition Act also allowed the Postmaster General to refuse mail that met any of the offenses mentioned in the Act itself.

The Sedition Act and the Espionage Act were really the same thing, having the Sedition Act being a set of amendments to the Espionage Act.  During the war, there were around 1500 prosecutions under the Espionage and Sedition Act, resulting in 1000 convictions.  These Acts were only applicable during times of war, and they were repealed on December 13th, 1920.

Imperialism in the United States

Imperialism is an economic system where a bigger country takes control of a smaller, weaker country that has valuable resources. The bigger, more developed country then uses the smaller country's resources to become an economic power. The bigger country sometimes uses military force to keep control, and this can sometimes lead to revolts against the bigger country. The system is only beneficial to the country in control.

I do not think that the US should have been imperialist in 1900. Doing so would have undermined everything that the constitution stands for; individual liberties. Just having gone through a war with ourselves over individual freedom, it would have been very hypocritical.  Fighting off opression and then turning around and opressing another country was not what America was about.  The US also had just gone through an industrial revolution, so the US had factories and sufficient resources to sustain themselves.  There was no need for the U.S to be imperialist and it would have gone against what the Constitution was based on, individual freedoms.

Sources: my head, Eyewitness to History, p. 318
 http://mossiso.com/2010/10/09/british-imperialism-and-gender-issues.html