[1] He was elected again to the South Carolina House of Representatives in 1876 and claimed to be the Speaker after a tumultuous campaign in the state, marked by violence and intimidation.

[2] Following the South Carolina Supreme Court's decision to allow seating of elected legislators from Edgefield and Laurens counties, rival state governments assembled.

Mackey and the Republican legislators occupied the South Carolina State House with the support of Federal troops.

The order of President Hayes to remove Federal troops from South Carolina on April 10, 1877, a result of a political compromise ended the Republicans' struggle to control state government.

Mackey continued to be active in public life serving as an assistant United States attorney for South Carolina from 1878 to 1881.