In the 17th and 18th centuries Kerry became increasingly populated by poor tenant farmers, who came to rely on the potato as their main food source. As a result, when the potato crop failed in 1845, Kerry was very hard hit by the Great Irish Famine of 1845–49. In the wake of the famine, many thousands of poor farmers emigrated to seek a better life in America and elsewhere. Kerry was to remain a source of emigration until recent times (up to the 1980s). Another long term consequence of the famine was the Land War of the 1870s and 1880s, in which tenant farmers agitated, sometimes violently, for better terms from their landlords.