Why had African Americans lost many of the rights gained during Reconstruction by the late 1800s?
A) because of the growing power of Conservatives
B) because of northern efforts to maintain control
C) because of intervention by the federal government
D) because of the rise of white southern Republicans
*WILL MARK BRAINLIEST IF ANSWERED IN LESS THAN 10 MIN*

Hello There the Correct answer is D) because of the rise of white southern Republicans.

Reconstruction (1865-1877), the turbulent era following the Civil War, was the effort to reintegrate Southern states from the Confederacy and 4 million newly-freed slaves into the United States. Under the administration of President Andrew Johnson in 1865 and 1866, new southern state legislatures passed restrictive “black codes” to control the labor and behavior of former slaves and other African Americans. Outrage in the North over these codes eroded support for the approach known as Presidential Reconstruction and led to the triumph of the more radical wing of the Republican Party. During Radical Reconstruction, which began with the passage of the Reconstruction Act of 1867, newly enfranchised blacks gained a voice in government for the first time in American history, winning election to southern state legislatures and even to the U.S. Congress. In less than a decade, however, reactionary forces–including the Ku Klux Klan–would reverse the changes wrought by Radical Reconstruction in a violent backlash that restored white supremacy in the South.