In the 1840s, why did so many Irish people move to the United States?

C Ireland's potato crop failed due to a disease.

Irish people moved to the united states because Although the Irish potato blight receded in 1850, the effects of the famine continued to spur Irish emigration into the 20th century. Still facing poverty and disease, the Irish set out for America where they reunited with relatives who had fled at the height of the famine.