Could someone give me a brief definition of the civil war era? (1 or 2 sentences)

This is the political, social, cultural, and economic 'time and place' surrounding the creation of a literary text.

Read the following excerpt from life on the mississippi by mark twain. no girl could withstand his charms. he "cut out" every boy in the village. when his boat blew up at last, it diffused a tranquil contentment among us such as we had not known for months. but when he came home the next week, alive, renowned, and appeared in church all battered up and bandaged, a shining hero, stared at and wondered over by everybody, it seemed to us that the partiality of providence for an undeserving reptile had reached a point where it was open to criticism. how does twain's use of understatement serve his purpose? be sure to use specific details from the text to support your answer.

Mr. underwood's editorial defending tom robinson is surprising because he's described as not wanting to be near negroes it's a dangerous stance to take at that time he had been neutral during the trial he wasn't in the courtroom