Part A The California Gold Rush was an important discovery that contributed to the development and expansion of the United States. Prior to the Gold Rush California was a remote and sparsely populated area with no government control. People could come by sea or land which made it a great location when the Gold Rush exploded. The California Gold Rush brought 300,000 people across the United States to the West (Wikipedia, 2004). Of the 300,000 half arrived by sea and half came from the east overland on the California Trail and the Gila River Trail (Wikipedia, 2004). At first the gold nuggets could be picked off the ground. Later, gold was recovered from streams and riverbeds using simple techniques. Towards the end heavier equipment was used to retrieve the gold. When the gold was first discovered they wanted to keep it quiet. There was fear of what would happen to the land and agriculture if there was a mass gold search, but rumors spread and people saw the profits that could be made. Many hurried to set up stores to sell gold digging supplies and then announced and spread word of gold. It didn’t take long for this exciting news to take off. Soon all the newspapers along the east coast were reporting the findings and wealth to be made in California. The effects of the Gold Rush were substantial. In six years, San Francisco grew from a small settlement of about 200 residents to a boomtown of about 36,000 (Udall, 2003). Roads, churches, schools and other towns were built throughout California. Soon it then became a state and railroads were built across the country from California to the eastern part of the United States. Agriculture and ranching expanded to meet the needs of the people. New technologies were developed and soon the economy in the West took off. Another geographic factor that affected the United States was the Dust Bowl. It was a period of severe dust storms causing major ecological and agriculture damage to American and Canadian prairie lands. Severe drought combined with bad farming methods caused this terrible phenomenon. Without natural anchors to keep soil in place, it dried, and turned to dust which blew away with high winds. Millions of acres of farmlands were damaged. Hundreds of thousands of people were forced to leave their homes. Many migrated from Oklahoma to California and other states. This was the largest migration in American History within a short period of time(Wikipedia, 2004). The government got involved and emergency relief programs were created to help conserve soil, feed and clothe the poor and hungry. Trees were planted to help break the winds, hold water in the soil and hold the soil itself in place. Part B The Indus River Valley contributed to the development of a large urban civilization. It is one of the worlds earliest civilizations and at its peak had a population of well over five million (Wikipedia, 2004). The Indus River is a major river that flows through Pakistan and is set between mountains, desserts and the ocean. It is the key water resource for the economy. Because of its rich agriculture lands the Indus Valley could grow many crops. The river provided irrigation to the fields and allowed easy transportation. Once they were established and could feed their own residents they started to trade. Trade networks linked their culture with related regional cultures. They developed new technologies and were the first civilization to have wheeled transport. They invented new techniques in handicraft and metallurgy and are known for their cities built of brick, roadside drainage systems and multistoried homes. The uniformity and standards that were used to make the bricks helped add to the success of their buildings. They were able to develop urban centers which made it a place for people to work. Technology and ideas were able to flourish. This made life easier and more enjoyable which brought people to this area. There are many theories about why people left the Indus River Valley. Some say that mudslides altered the course of the river and blocked irrigation so that they could no longer provide for themselves (Mountjoy, 2004). Others say that the mudslides created swamps that attracted mosquitoes and spread disease (Wikipedia, 2004). Invasion of Aryans, drought, decline in trade and climate change are all theories as to why the diffusion of the Valley took place. The civilization in the area declined and many residents then migrated east. Although we don’t know for sure why the people left this area we do know that at one point it was the largest civilization in the world. It was a peaceful place and because of their brick buildings and technology advancement people were drawn there. Their economy was strong due to trade. The land between the Tigris and Euphrates Rivers called the Mesopotamia is an example of cultural diffusion. The main source of success for the growth in this area was the rivers. The deposits from the flooding of the rivers left the soil very fertile and great for agriculture. The climate, water supply and rich fertile soil assisted in the developments of agriculture settlements in this area. There were frequent spring flooding with no cliffs or embankments to keep water from spreading at will. Nature was this areas worse adversary. Over time new technology with irrigation found its way into the Mesopotamia. Now that the people could control the water, this led to the development of farming and agriculture. They could now support a large population. Many people were drawn to this area and cities were built and governments were formed. The Sumerian people of this area were most remembered by their writings. They developed the first calendar and writing called cuneiform. They used tablets made from clay to sketch on. Over time this writing became a part of everyday life. It was used in business transactions, letters, prayers, dictionaries, math, etc. When the Sumerians were conquered by King Sargon they lost their independents and soon disappeared, but their language of culture continued to live on. Their writings, knowledge and ideas continued to spread westward.

References:
Hollar, Sherman (2011). Ancient Civilizations: Mesopotamia. Chicago, Il: Encyclopedia
Britannica, Inc. Retrieved from ebrary.com/lib/westerngovernors/doc.
Mountjoy, Tim (2004). River in World History: Indus River. New York, NY: Chelsea
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Udall, David (2003). Forgotton Founders: Rethinking the History of the Old West.
Covelo, CA: Island Press. Retrieved from ebray.com/lib/westerngovernors/doc.
Wikipedia: The free encyclopedia (July, 2004). FL: Wikimedia Foundation, Inc.
Retrieved from http://www.wikipedia.org.