What are the advantages and disadvantages of studying history beginning with Reconstruction 1877 until 2013?

The Advantages of Reconstruction was that United States became a Unified nation.

The Disadvantages were that it failed to remove slavery.

Explanation:

The success of the reconstruction was that a new constitution was made by all the states agreeing to the 13, 14, and 15 amendments and forming one united constitution.

But the failure of reconstruction was that the slaves could not be saved from the white prosecution and the legislature had no rights for the slaves and slavery kept going on as the black farmers were bound to work for the white owners.

These were some advantages and disadvantages of studying history beginning with reconstruction.