Blacklion's urban growth was hampered until the mid nineteenth century by the nearby village of Red Lion, some miles to the west on the coach-road to Sligo. The weather event known as The Night of the Big Wind in January 1839 caused structural damage to the Protestant church at Thornhill, to the west of Blacklion. This was never fully repaired. According to local tradition Blacklion was the first place in Co. Cavan to be affected by the potato blight in the autumn of 1845. Deaths as a result of malnutrition and disease in the subsequent Great Famine were high.