• Atlas of the Great Irish Famine, p48-49
  • Atlas of the Great Irish Famine, p53
  • Atlas of the Great Irish Famine p426

The Irish marriedquite young, girls at 16, boys at 17 or 18, and tended to have large families,although infant mortality was also quite high.

The History Place - Irish Potato Famine: Introduction

The History Place - Irish Potato Famine

Poor Irish laborers, more than anyone, becametotally dependent on the potato for their existence.
The famine caused mass migration, as about 1.5 million people fled the country, mostly to north America. This mass migration, which continued throughout the 19th and early 20th centuries, triggered a permanent demographic decline in the Irish population, which fell from about 8 million in 1840 to about 4 million in 1900. It also constituted the fatal blow to the Irish language, spoken by up to half the population before the famine but only 15% by 1900.

Great Famine (Ireland) - Wikipedia

The spark that lit the fuse was the arrival in September 1845 of the potato blight.
A couple of clarifications on the foregoing:
Sir Charles Trevelyan was not the Treasurer in Russell’s cabinet – that was, as Chancellor of the Exchequer, Sir Charles Wood, Trevelyan, a civil servant and not a politician, being Under Secretary at the Treasury. As such Wood was his superior and the principal decision maker with regard to Treasury matters. Trevelyan had also held this post during the previous Peel administration.
In her biography Robin Haines (Charles Trevelyan and the great Irish Famine) defends Trevelyan’s performance in a (somewhat, at times) convincing manner. It is definitely wort reading.
A very interesting statistic regarding the impact of the Famine on deaths and Irish Population growth is that on the eve of the Famine (1841 census) Ireland constituted nearly one third of the UK population. A mere 70 years on (census of 1911) it was a bare tenth of the same population – i.e. in one lifetime! This fact helps to reflect, if somewhat overstate) the births foregone due directly to the Famine and subsequent emigration.

 

BBC - History - British History in depth: The Irish Famine

The Great Irish Potato Famine by James Donnelly (Sutton Publishing, 2002)
The response of the British Government, directly responsible for governing Ireland since 1801, was also unsatisfactory. Their decision to drastically cut relief measures in mid-1847, half way through the famine, so that Irish tax payers, as opposed to the Imperial Treasury, would foot the bill for famine relief, certainly contributed greatly to the mass death that followed.


They did however have to continue to pay rents either in cash or in kind, to landlords. Failure to do this during the famine saw many thousands being evicted, greatly worsening the death toll.


The Irish famine of 1879 was the last main Irish famine

However, the crisis was greatly compounded by the social and political structure in Ireland in the 1840s. Most poor farmers and agricultural labourers or ‘cottiers’ lived at a subsistence level and had little to no money to buy food, which was widely available for purchase in Ireland throughout the famine years.

The Irish Famine was Genocide - Irish History Links

‘On arriving at Cappagh I found the coast-guard and his wife (a tidy little Englishwoman) placed under circumstances almost as pitiable as the poorest of those who surrounded her, inasmuch as she was daily witnessing absolute starvation without the means of relieving it. Within a few yards of the coast-guard house were three families which I saw starving to death. Moore, the coast-guard, told me that he had buried numbers of bodies himself—that he was obliged to do so in self-defence, for fear that they should breed a pestilence. In the first house I entered I saw a dead child lying in a corner of the house, and two children pale as death, with their heads hanging down upon their breasts sitting by a small fire. Mrs. Moore, who accompanied me into the house, told me the sad history of the family. The father had died on the road coming home from work. One of the children, a lad seventeen years of age, had been found in the absence of his mother who was looking for food, lying dead, with his head leaning on the hob close to the fire, and with his legs held out of the fire by the little child which I then saw lying dead. Two other children had also died. The mother and the two children still alive had lived on one dish of barley for the last four days. For these famished children I obtained from Mrs. Moore a cake of brown bread, and sent it to them by the mother. In about a minute after I entered the house again, to see whether they were eating this cake voraciously, and found the children sitting in the same posture. I feared they had not got the bread, but they had devoured it. I questioned them closely—asked them what colour it was. The child who replied said it was black; it was coarse brown bread.

What Caused the Irish Potato Famine? | Mises Institute

The short term cause of the Great Famine was the failure of the potato crop, especially in 1845 and 1846, as a result of the attack of the fungus known as the potato blight. The potato was the staple food of the Irish rural poor in the mid nineteenth century and its failure left millions exposed to starvation and death from sickness and malnutrition.