America was created given the dissatisfaction many felt with the European control held over the colonies once begun in the New World. Given this dissatisfaction, the colonists began to separate themselves from Europe in many different ways. One way the colonists began to separate themselves from Europe was through their literature. The first movement of literature in America was the Puritan period. (On a side note, many critics cannot agree upon specific dates of literary periods. Some dates may differ from what others have stated as belonging to a specific period.)
The Puritan period (1472-1750) was wholly based upon private letters, personal diaries/journals, religious texts, and sermons. One example of a text from this period is Jonathan Edwards' sermon "Sinners in the Hands of an Angry God." Angered by the sin in his community, Edwards constructed a sermon meant to use fear to bring them back to God.
Following the Puritan period was the Enlightenment (1750-1800). It was during this period that literature moved away from religion and towards science and logic. Again, these texts were mainly letters, speeches, and documents of the political nature.
It was not until the American Romantic period (1800-1860) that literature came to be more recognizable as creative and artistic. The American Romantics wrote about the importance of imagination, nature, and individuality.
In essence, the literary periods of America were defined by the establishment of America as an independent entity. The literature of the period mirrored the concerns of the population as a whole. Early literature mirrored the need for religious freedom, moving into new ideas as the nation came to desire independence from England. After independence, the literature mirrored the ideas felt by the writing community about the importance of the individual (given the country's identity had previously been established).