DID you know there was a disastrous event that hit Ireland between 1845 and 1849? It was known as The Great Famine. It caused at least one million deaths and triggered the migration of 2.5 million people due to potato crop failure. The crops failed due to disease. The disease called late blight came from North America.
The late blight is caused by a water mold Phytophthora infestans which make potatoes inedible. The disease had completely wiped out about half of the potato crops in 1845, leaving only a few healthy ones for harvesting a year after.