what factors led to the failure of Republicans to secure rights for freedmen in the South in the years between 1865 and 1877

Check these sites.

http://www.pbs.org/wgbh/amex/reconstruction/activism/ps_calhoun.html

http://www.123helpme.com/view.asp?id=22950

http://www.history.rochester.edu/class/douglass/part5.html