In January 1865, Congress proposed an amendment to the Constitution which would abolish slavery in the United States.  On December 18, 1865, Congress ratified the Thirteenth Amendment formally abolishing slavery.  

The Civil War ended on April 9, 1865.  Abraham Lincoln was assassinated less than one week later. Andrew Johnson, Lincoln's Vice President,  briefly continued Lincoln's policies after Lincoln's assassination and in May 1865 announced his own plans for Reconstruction which included a vow of loyalty to the Nation and the abolition of slavery that Southern states were required to take before they could be readmitted to the Nation.

Black codes were adopted by midwestern states to regulate or inhibit the migration of free African-Americans to the midwest. Cruel and severe black code laws were adopted by southern states after the Civil War to control or reimpose the old social structure.  Southern legislatures passed laws that restricted the civil rights of the emancipated former slaves. Mississippi was the first state to institute laws that abolished the full civil rights of African-Americans.  "An Act to Confer Civil Rights on Freedmen, and for Other Purposes,"  a very misleading title, was passed in 1865.  Other states quickly adopted their own versions of the codes, some of which were so restrictive that they resembled the old system of slavery such as forced labor for various offenses.

The Bureau of Refugees, Freedmen and Abandoned Lands (or the Freedmen's Bureau) was organized to provide relief and assistance to the former slaves, including health services, educational services, and abandoned land services. Congress passed an act on March 3, 1865 to establish the Bureau of Refugees, Freedmen and Abandoned Lands.  The program was administered by the Department of War and was first headed by General Oliver Otis Howard who was appointed to the position on May 13, 1865 by President Abraham Lincoln.

Although Congress responded with legislation that led to the Civil Rights Act of 1866, States kept on the books laws that continued the legacy of the black codes and, therefore, second-class citizenship for the newly freed slaves. In 1866, the Civil Rights Act was passed by Congress which outlined a number of civil liberties including the right to make contracts, own and sell property and receive equal treatment under
the law.

Congress passed the Fourteenth Amendment in 1867. The amendment was designed to provide citizenship and civil liberties to the recently freed slaves.  

The first Reconstruction Act was passed by Congress on March 2, 1867.  Five military districts each under the leadership of a prominent military general were carved out in the south and new elections were held which allowed the vote to black males.  

Carpetbagger was the name given to Northerners who came south for political and economic reasons.  They were considered corrupt individuals who were using Reconstruction as a means to advance their own personal interests.  Many of the Northerners were middle-class individuals who were professional people who decided to move to the South to make their mark. Others were soldiers of the Union army who stayed in the south at the conclusion of the war.  During the period of Reconstruction, fifty-two of the sixty individuals who served in the Congress were ex-Union soldiers.  Some of these people were asked to run for office by former slaves.

Black Northerners also ventured south.  Some of them were veterans of the Civil War, others were teachers, ministers and returning children of free blacks who had been educated in the north including "Black carpetbaggers" born in Great Britain and Dutch Guiana and had been elected members of Congress.  More than 100 blacks held public office after the Civil War.