Looking back through a history of the electoral college, many of the states did not at first actually have a popular vote to decide the electors for president. Instead many states chose electors by having the state legislative branch choose the Electors for their state, with only a few of the states putting the decision to a popular vote.
For example in the 1800 election of Thomas Jefferson, only Kentucky, Maryland, North Carolina, Virginia, and Rhode Island held a popular vote, with all other states having the legislative assembly decide the electors (except Tennessee which had an unique system).
However, over the course of a couple of decades, most states switched to a popular vote, excepting South Carolina. South Carolina continued to have the legislative body choose the electors all the way until the end of the Civil War, where upon they started using a popular vote to decide electors.
What were the reasons for South Carolina to not use a popular vote to decide the Electors for so long compared to other states and why did they finally decide to put the decision to a popular vote in future elections after the Civil War?