On September 28, 1868, a mob of Democrats massacred nearly 300 African-American Republicans in Opelousas, Louisiana. The savagery began when racist Democrats attacked a newspaper editor, a white Republican and schoolteacher for ex-slaves. Several African-Americans rushed to the assistance of their friend, and in response, Democrats went on a “Negro hunt,” killing every African-American (all of whom were Republicans) in the area they could find. (Via Grand Old Partisan)
Democrats in hoods slaughtered hundreds of Republicans and blacks across the country.
On April 20, 1871 the Republicans passed the anti-Ku Klux Klan Act outlawing Democratic terrorist groups.