I'm not sure how to distinguish between some of these (whether they're social or political) but here goes:

Social:

• Belief that the Protestantism was better than Catholicism or any other religion.
• Ethnocentrism -- the belief that white Americans were superior to non-whites
• Belief that small farmers were the salt of the earth and Americans should all have small farms

Political

• Belief that democracy was the best form of government
• Desire to gain more power
• Need to give people more land so they would be satisfied and like the government

Economic

• Desire to gain the natural resources of the West
• Need for more land to settle a growing population
• Individuals' desire to get rich

The best way to approach this question is to pose another question to it.  When defining characteristics about social, political, and/ or economic realities, posing operational based questions about how such conditions operate might prove to be helpful.  For example, in establishing three political characteristics, ask yourself, "What role does government play in this political setting?" Another question one can ask, "How high of a value do individual rights play in this political setting?"  Finally, a question to be asked about political settings could be, "How is power exhibited or represented in the political setting?"  The answers to each question could reveal much in way of political characteristics.  Economic questions could be, "Who or what owns the means of production?" or "How is personal wealth treated?"  or "How are taxes determined?"  would reveal characteristics about economy.  Finally, when examining social characteristics, ask questions such as "What ideals does the society uphold over all?" Another such question would be, "What are some notions upon which the society frown?"  A last question which is certain to reveal social characteristics would be, "What type of people are revered in this social setting?"  Again, in posing questions, our answers become the characteristics for which we strive.