The book includes many pages of tables from surveys, censuses and information gleaned from headstones. They make for dry reading but they contain a wealth of information.
The richer families of the area have left further records, such as wills etc, but much can be pieced together about the less well off from the tables presented, from headstones and from family recollections.
More information lies in parish records and files held by government departments such as prison and court records. The Royal Irish Constabulary collected data on changes to crops planted during the Famine. Overseas governments recorded arrivals to their jurisdictions. Electoral rolls and other official documents sometimes allows finding the fates of people after they had left Ireland.
None of these records are totally accurate or necessarily complete - they were compiled by people and people slip up now and then. However, sometimes the same fact appears from more than once source and becomes more certain.
About the Author's
This book was researched, written and edited by Tom Hickey, John Keane and Brian Corry. The authors are not professional historians, and the book is not an academic work. It set out to explore aspects of life there over the centuries and to bring together what they could discover.