Modernism
During the 20th century a communications revolution that introduced motion pictures, radio, and television brought the world into view—and eventually into the living room. The new forms of communication competed with books as sources of amusement and enlightenment. New forms of communication and new modes of transportation made American society increasingly mobile and familiar with many more regions of the country. Literary voices from even the remotest corners could reach a national audience. At the same time, American writers—particularly writers of fiction—began to influence world literature.
The 20th century saw the emergence of modernism. Modernism responded to the world’s complexity by asserting that the individual had the potential to achieve a broader perspective than that offered by any one society or its history. Although realism, naturalism, and regionalism were still viable modes of expression, they reflected the increasingly complex reality of 20th-century society. Immigration and industrialization led to increasing urbanization, and, in turn, to class stratification.
Theme:
Some writers examined the sometimes complex psychology of America’s elite, other writers turned to the psychological and physical reality of the laboring classes, whose ranks continued to swell with high rates of immigration in the late 19th and early 20th centuries. Several American authors who are sometimes known as social realists looked at working conditions, often for the purpose of social reform.
A period of disillusion and cynicism that followed World War I (1914-1918) found expression in the writings of a group of Americans living in Paris who became known as the Lost Generation. They shared a bitterness about the war, a sense of rootlessness, and dissatisfaction with American society. They portrayed the emotional exhaustion of this generation and their seemingly vain search for meaning and value in life.
Some other writers focus on the overwhelming forces of nature and on issues of class.
Gender issues remain major topics in 21st century American literature, and more gay and lesbian authors are publishing their work and bringing their community and concerns into focus. Characteristics
1. Diversity
The reading audience of the United States changed as social and economic realities changed. Immigrant populations added great variety to 20th-century American fiction. American literature at the is exceptionally diverse, with rapidly growing multicultural influences. New voices continue to emerge within the Native American, African American, Asian American, and Hispanic American communities.
After the 1960s it became increasingly difficult even to define a mainstream.
Jewish-American literature: among the first to record their experiences.
African American literature: focuses on slavery and its legacies while also offering hope, particularly in the strength of bonds among women.
Native American literature: reassesses the experience of their cultures.
Hispanic American literature.
Asian American authors brought strong voices to American literature after the 1960s. Much of Asian American literature deals with the inevitable conflicts experienced by those who bridge two cultures.

Modernity and Americanization are typically the realm of youth, while traditional culture and history remain the dying province of their elders.
While creating unique worlds for various distinct communities, America’s diverse literary voices continue to reflect the unique characteristics of its land, people, and culture.

2. Regionalism
The vastness of the United States and the great diversity of its people have always been reflected in its literature. This was especially true in the 20th century, which witnessed the blossoming of strong regional traditions in the West and the South.
The South was also rich in women writers during the 20th century.

3. Bilingualism.
Many American authors incorporate a lot of their mother tongue language into their writing. This reflects both the alienation and the strong cultural identity that comes from being a nonnative English speaker in the United States.

4. Style
Writing is noted for innovations in narrative style, such as simplification and fragmentation of plot and the use of unconventional syntax and punctuation. Representatives:
Henry James
Theodore Dreiser
Sinclair Lewis
Ernest Hemingway and F. Scott Fitzgerald,
William Faulkner,