Accurately listing the chronology of literature is a highly academic task, but it is possible to simplify the process. Literature has been around for centuries, and there have been millions of writers that have come and gone. It is easy to see that the prevalent culture and condition of society also affects the work of prominent authors of each time, and it is also apparent that there was a common theme between various works of similar periods.
Over the years, American literature has progressed by leaps and bounds, and every year there are new ideas and even new words created by contemporary authors. There are many historians and academicians who have dedicated their entire lives to studying the progression of literature and American history over time.
Before the Twentieth Century
No one knows the exact answer to when and where literature was born. But, it is possible to pinpoint the changes in themes and writing moods over the years.
Puritanism: 1620-1730 A.D.
This was a highly religious time. The main focus of literature here was theism and the proclamation of faith and belief in God. Everyone lived pious lives at this time, and believed in the power of the Gospel; this showed in the manner of writing as well. A majority of literary works were concerned with love and brotherly affection, and some also dealt with witchcraft and other 'Anti-God' rituals. Some famous authors of this time were Jonathan Edwards, William Bradford, Anne Dutton, and Samuel Rutherford.
Colonialism and Enlightenment: 1740-1820 A.D.
In this era, traditional thoughts were discarded and scientific and empirical proof was demanded for various happenings. The increase in scientific knowledge of the time played a huge role in this development, and natural laws of the world were viewed under a new light. Rather than focusing on an individual's religious thoughts, society started concerning itself with democracy and other forms of social development instead. Notable authors were Benjamin Franklin, Samuel Adams, Phillis Wheatley, Thomas Jefferson, and Thomas Paine.
Romantic: 1820-1860 A.D.
Romanticism here does not refer to the mushy perspective that we possess today; it talks about the focus on individualism and the liberation of the soul instead. At this time, God was viewed as an entity fused with nature, and this changed people's points of view drastically. Rather than focusing on the outside world, the focus here shifted to one's inner self, and the process of self actualization began. Philosophy and transcendentalism also saw a massive upsurge in this time. Notable authors of this time were Henry David Thoreau, Ralph Waldo Emerson, Nathaniel Hawthorne, Herman Melville, and Edgar Allan Poe.
This period further saw the transformation of literature into various critiques of slavery, a lot of regionalism, south-western humor, realism, and naturalism.
Modernism: Since the 20th century
Industrialism and other factors led to a rapid rise in the intellect and awareness of people, and hundreds of new genres started appearing in literature. Existentialism and scientific thought also started taking precedence, and this showed in the works of notable authors of the time―Charles Darwin, Ernest Hemingway, Sigmund Freud, Thomas Fitzgerald, and Karl Marx. As society grew, more and more people started feeling alienated and aloof, leading to a loss of faith in God and other religious works.
Soon after this, post-modernism took over, and that is the period that we find ourselves in today. There are so many genres surrounding us today simply due to the universal nature of information. It would be impossible for the literature from any one particular region today to not be influenced by the writing of another region. The borders have now been eradicated, and this has led to a complete change in the literature we see today.
Please note that there are many smaller periods and many lesser known authors than the ones mentioned here. This article focuses on American literature, without taking into consideration literature from other parts of the world.