In 1829 Daniel O'Connell won rights for Irish catholics by pushing through a repeal of the act of Union. In practice this meant that the Irish could now sit in English Parliament. Ireland was always dependent on the potato crop as there main source of food. The famine was the result of many crop failures and the insufficient amount of relief for stopping the outbreak of starvation and disease. The famine was the most tragic and significant event in Irish history and one of the worst human disasters of the nineteenth century. Ireland depended on the potato for food, as it was a very suitable crop to be grown in the country. This was about the only food the people of Ireland could afford as the British landlords charged a very high and unfair rent which did not leave much money to live on. The population had increased rapidly and had reached 8 million by 1841. Two-thirds of these depended on agriculture and the potato. The failure of the potato crop in 1845 was disastrous. The crop failed again in 1846, 1847, and 1848. 1847 was the worst year of all and was known as Black '47. By 1851, the population of Ireland had been reduced by more than two million due to starvation, disease, and emigration to Britain and North America. The people who travelled to North America went on coffin ships, so-called because a lot of the people travelling on them died from spreading diseases and never reached their destination.