Question

Why did Reconstruction include the Thirteenth, Fourteenth,
and Fifteenth Amendments?

Answer 1

The reason that those 3 specific amendments is because they were ratified to establish political equality.  

Answer 2

Between 1865 and 1870, during the historical era known as Reconstruction, the Thirteenth, Fourteenth and Fifteenth Amendments to the U.S. Constitution were ratified to establish political equality for all Americans. Together, they are known as the Reconstruction Amendments.