急what is American Realism?

急what is American Realism?
要英文的,归纳得精简点哦,要定义,特点,和举例说明：代表作家例子一两个.总觉得自己归纳得不好,认真回答啊,读书的事情不是开玩笑的哦.

In American literature,the Civil War brought the Romantic Period to an end.The Age of Realism came into existence.It came as a reaction against the lie of romanticism and sentimentalism.Realism turned from an emphasis on the strange toward a faithful rendering of the ordinary,a slice of life as it is really lived.It expresses the concern for commonplace and the low,and it offers an objective rather than an idealistic view of human nature and human experience.
Mark Twain, William Dean Howells,Henry James