Ireland has over 8000 years human occupation, so there is a lot of history there. Much happened before that, so a huge amount of things have happened in Ireland. Therefore your question is impossible to answer in detail.
the Normans took over between 1169-1500 government, society, economy, religion and connections to the world
A disease called Potato Blight destroyed the potato crops causing great famine. Many people left the country to live in the US or UK.
A lot
Many things, but most significantly, the famine.
the Great Famine
The potato famine was in Ireland at that time.
I think 16
The famine that lasted from 1845 to 1852.
2010-1845 is 165 (years between those two years)
between 1845 and 1851 over 15000,000 people emigrated from Ireland which was more than had left in the previous half century
They arrived in between 1845 to 1860 the immigrants where from Ireland and Germany
one was the Mexican War
John Tyler became president
Ireland was ruled by the UK appointed Lord Lieutenant who represented Queen Victoria in Ireland. In 1845 the Lord Lieutenant was Lord Heytesbury.
Mass starvation, disease and emigration in Ireland between 1845 and 1852, occurred during the Great Famine (known as the Potato Famine outside of Ireland), when potato blight devastated the Irish staple potato crop.