On July 4, 1876, (in the midst of a heated Reconstruction era local election season) a Black militia was engaged in military exercises when two white farmers attempted to drive through. Although the farmers got through the military formation after an initial argument, this event provided the excuse sought by whites to suppress Black voting through violence.
On July 6, in a courtroom, the farmers charged the militia with obstructing the road.
The case was postponed to July 8, by which time more than 100 white men from local counties had gathered in town, armed with weapons. The African Americans attempted to flee, but 25 men were captured and six were murdered.
Read more about the Hamburg Massacre at BlackPast.org. Also, read an extraordinary story by the South Carolina Citizen History about the historic markers for the Hamburg Massacre and about Senator Ben Tillman who led the mob attack.
Note that the plaque, pictured on this page, identifies political parties. For further context regarding the party realignment that occurred in the 20th Century, leading the vast majority of African Americans to change party identification from Republican to Democrat, visit the History, Art & Archives of the US House of Representatives.