With the beginning of Radical Reconstruction, southern African-Americans in the late 1860s and early 1870s took direct action to remedy long-standing grievances. These actions included:A. sit-ins that helped to integrate horse-drawn streetcars in southern cities. B. protest marches that desegregated public school systems in all the Upper South states. C. violent attacks to intimidate Democratic voters from participating in politics. D. the creation for the first time of all-black churches. E. a series of lawsuits that resulted in the U. S. Supreme Court's declaring segregation unconstitutional.