1. Industrialization
2. Economic Opportunity
3. Technological Change
4. Immigration
<span>During an unrestricted submarine warfare, one of the German U-boats had sunk the British passenger ship ,the Lusitania, at great loss of life. Public outcry in the U.S. led to America declaring war on Germany.</span>
Cahokia was one of the largest and possibly the capital city of the people that are referred to as the Mound Builders. Cahokia's size and the large number of people that lived there led to the main issues. Bad droughts and poor harvests meant people couldn't eat.
<span>Russian Sturgeon is a ancient species of fish which is about 4 meters long. The fish is a rare one with bones in it and weighs about 160 kg. They usually found near Bulgaria, Russia and Turkey. The population the Russian sturgeon further declined because of the construction of dams on the Volga</span>
