potatoes became the main food in Ireland. Then, in 1845, a disease killed all the potatoes in Ireland. Two million people died of hunger. Many Irish who did not die came to the United States at this time. Over a million Irish came to America; one of them was the great-grandfather of John F. Kennedy. In other parts of Europe, people did not want to change their old food habits. Some preferred to die of hunger rather than eat potatoes. In 1774, King Frederick of Germany wanted to stop his people from dying of hunger. He understood that potatoes were a good food, so he told the people to plant and eat potatoes or else his men would cut off their noses. The people were not happy, but they had no choice and so started to eat potatoes.