The economic systems of the first American societies were very similar. One such society, the Maya, lived in southern Mexico and northern Central America from the 3rd to 10th centuries CE, and depended on trade in goods such as obsidian and crops such as cocoa beans. Another American civilization was the Aztec civilization. They were located in the Valley of Mexico between the 13th and 16th centuries CE and used slash-and-burn agriculture to plant crops for trade. The Inca Empire existed from the 13th to 16th centuries CE along the Pacific coast of South America, near the Andes. The Incas used terraced agriculture and irrigation to grow crops such as corn. The economies of these early American civilizations relied heavily on trade and agriculture. The ancient Mayan civilization had an advanced trading system consisting of short, medium and long trade routes and a large market for a wide range of goods and materials. Modern researchers have used a variety of methods to understand the Mayan economy, including evidence from excavations, illustrations on pottery, scientific "fingerprints" of materials such as obsidian, and examination of historical documents. The Mayans did not use the term "money" in today's mentality; there was no globally accepted form of currency that could be used anywhere in the Mayan region. Even valuable items, such as cocoa beans, salt, obsidian, or gold, typically varied in value from one region or city-state to another, often increasing in value as they went. that these objects were far from their source. There were two types of goods presented broadly by the Maya: prestige items and subsistence items. Prestige items were things like jade, gold, copper, highly decorated pottery, ritual items, and any other less practical items...... middle of paper ......ntType= None&sort=RELEVANCE&inPS=true&prodId=GVRL&userGroupName= lom_liggett&tabID=T003&searchId=R1&resultListType=RESULT_LIST&contentSegment=&searchType=BasicSearchForm¤tPosition=4&contentSet=GALE%7CCX3406400067&&docId=GALE|CX3406400 067&docType=GALE.Minster, Christopher. “The ancient Maya: economy and trade”. About.com. Accessed May 5, 2014. http://latinamericanhistory.about.com/od/Maya/p/Ancient-Maya-Economy-And-Trade.htmSharer, Robert J. “Mayan Shamans and Priests.” In World History: Ancient and Medieval Eras. ABC-CLIO, 2004-. Accessed May 5, 2014. http://ancienthistory.abc-clio.com/World History: Ancient and Medieval Eras, sv “The Inca (Overview)”. Accessed April 30, 2014. http://ancienthistory.abc-clio.com/.World History: Ancient and Medieval Eras, sv "Mayan Civilization (overview)." Accessed May 6, 2014. http://ancienthistory.abc-clio.com/.