CREATE TABLE table_6784 ("Institution" TEXT, "Location" TEXT, "Founded" FLOAT, "Type" TEXT, "Enrollment" FLOAT, "Nickname" TEXT, "Joined" TEXT, "Left" TEXT, "Current Conference" TEXT)

What joined that was founded prior to year 1856 and whose current conference is the Big South (NCAA Division I)?
SELECT "Joined" FROM table_6784 WHERE "Founded" < '1856' AND "Current Conference" = 'big south (ncaa division i)'
SELECT "Joined" FROM "table_6784" WHERE "Current Conference" = 'big south (ncaa division i)' AND "Founded" < '1856'