Democrats
The first answer stated above is wrong about the 1866 elections. In that year the moderate Republicans lost ground to the Radical Republicans who effectively gained control of the US Congress.
During the Radical Reconstruction period in the United States following the Civil War, the group that had the smallest roles were likely the Southern white Democrats who opposed the policies of the Republican-controlled Congress. These Democrats, who were largely supportive of the pre-war social and political order, were marginalized and excluded from political power during this time. As a result, they had limited influence on the direction of Reconstruction policies and initiatives.
the election of 1967 with thomaos jefferson.
sharecropper
The most well know extremist group during reconstruction was the Klu Klux Klan or the KKK.
Andrew Johnson's group had the harshest reconstruction plan after the Civil War. This did not include any protection for people who had been slaves.
Seleucid kings. Sources: My world history book :)
Carpetbaggers and scalawags gained the most from reconstruction.
KKK
2,7 using klm configuration.since it is the first in group 7
slaves and former slaves
African Americans
Ku Klux Klan...