How did the memory of the American Civil War and Reconstruction period shape American life in the late 19th and early 20th century?
The late 19th and early 20th centuries were largely a period of retrenchment for civil rights, meaning that civil rights did not move forward appreciably, despite the efforts of civil rights leaders such as W.E.B. Du Bois. Part of what caused civil rights to stall was people's reactions to the Civil War and Reconstruction, as they believed that they had already worked to advance civil rights and that there was not much more the government was willing to do.
During the Civil War, the Emancipation Proclamation of 1863, passed by Lincoln, outlawed slavery in the Confederacy. This law became the 13th Amendment, which outlawed slavery everywhere after the Civil War. In addition, the 14th and 15th amendments gave all people born in the U.S. citizenship and allowed all men to vote, respectively. During Reconstruction, the Confederate states were readmitted to the Union and had to pass these new amendments. However, the south did not reconstruct its economy, and freed slaves were largely employed as sharecroppers after the war and were poor and landless. There was very little willingness to change after the efforts and money the government had put into fighting the Civil War and carrying out the program of Reconstruction, which had divided the south into military districts. Instead, Jim Crow laws imparted a system of inequality in the south, and Supreme Court cases such as Plessy v. Ferguson of 1896 allowed separate but equal facilities and opportunities for African-Americans (though the facilities were not equal in reality).
During this time period, the federal government was largely inactive in many ways. One of their major tasks was to pay pensions to Civil War veterans, but they didn't carry out many major reforms until the Progressive Era with Teddy Roosevelt in the early 1900s. Instead, during the Gilded Age, monopolistic businesses were allowed to grow with very little regulation.