Short answers, pulled from the story.
The Great Famine in Ireland occurred between 1845 and 1852. The potato blight first appeared on the Isle of Wight in August 1845, and reports of cholera in potatoes reached Irish newspapers by mid-September 1845.
Modern historians estimate that at least one million people died during the Great Famine in Ireland. Estimates range from 775,000 to 1.5 million deaths, with most dying from disease including cholera in the latter stages of the crisis.
Land management was handled through a middleman system introduced in the 18th century where agents collected rent from tenants while landlords received fixed income. Many absentee landlords lived in England and sent revenue back there, such as the Earl of Lucan who owned over 25,000 acres.
A census taken in 1851 counted 6,552,385 people, representing a drop of over 1.5 million from the 1841 figure of 8,175,124. Between 1845 and 1855 at least 2.1 million people left Ireland, making it one of the greatest exoduses from a single island in history.
Of more than 100,000 Irish that sailed to Canada in 1847, an estimated one out of five died from disease and malnutrition including over 5,000 at Grosse Isle Quebec. These overcrowded vessels were known as coffin ships and sailed from small unregulated harbours in West of Ireland.