The correct answer is B) expanding and protecting African Americans' civil rights.
The political concern that dominated the period of Congressional Reconstruction was expanding and protecting African Americans' civil rights.
The Reconstruction period after the Civil War was from 1865 to 1877. Although with the victory of the Union's Army, slavery had ended and some acts supported and protected the civil rights of African Americans, the southern states were free to rebuild themselves. President Jackson indulgence over the southern states allowed these states to enact the black codes, that were laws to restrict the liberty of the African Americans.