Why did so many Irish immigrants come to the united states between the 1840's and 1860's?

ANSWER:  In the mid-1840s, the size and nature of Irish immigration changed drastically. The potato blight which destroyed the staple of the Irish diet produced famine. Hundreds of thousands of peasants were driven from their cottages and forced to emigrate -- most often to North America.

Explanation: Pushed out of Ireland by religious conflicts, lack of political autonomy and dire economic conditions, these immigrants, who were often called "Scotch-Irish," were pulled to America by the promise of land ownership and greater religious freedom. Many Scotch-Irish immigrants were educated, skilled workers.

The potato blight which destroyed the staple of the Irish diet produced famine. Hundreds of thousands of peasants were driven from their cottages and forced to emigrate.

b) they want the land taken away from the wealthy landowners and given to peasants.