Why did irish and german immigration to the united states increase in the 1840s?

The unrest, unemployment and hardships they were experiencing back home are the reasons for the massive Irish and German immigration in the 1840s. Specifically, there was famine in Ireland during this time because of continued crop failure. Meanwhile, German immigrants came seeking freedom from the economic turmoil, and the civil unrest that would eventually lead to the 1848 revolution. These groups would experience discrimination at first but would later successfully integrate with American society.