The Republican Party of the United States was founded during the 1850s in response to the political tensions that revolved around slavery and came to define that era. The Republican Party's goal was to abolish slavery and preserve the hierarchy of the national government over that of the states. The ensuing years were marked by an increasing divide between northern and southern states that eventually boiled over when the state of South Carolina seceded from the Union in 1860. Other southern states followed and the Civil War of the United States began in 1861 between the Union and the newly minted Confederacy. In 1865, the conflict ended with the Union as the victor. Following this, the southern and formerly Confederate states were gradually reintroduced back into the Union of the United States with a process that came to be called the Reconstruction Era of the United States. Northern Republicans and freed slaves came to control the politics of South Carolina during this era, as Confederates were temporarily disenfranchised. The planter elite struggled to adapt to a free labor system. The Republican Party of South Carolina was established during this time and controlled the politics of South Carolina throughout Reconstruction. Democrats mounted increasing violence and fraud at elections from 1868 through the period, in an effort to suppress the black and Republican vote. In 1874, the paramilitary Red Shirts arose as a paramilitary group working openly to disrupt Republican meetings, suppress black voting and return Democrats to power. The most violence occurred in counties where blacks were a strong minority, as Democrats tried to reduce their challenge.