Griffith’s Survey undertaken between 1824 & 1844 of boundaries and land valuation is the most complete all Ireland survey
The result is one of the most important databases available to anyone researching their Irish ancestors. The valuation was published consecutively on a county by county basis – see Griffith’s Valuation exact publication date by county between 1847 and 1864 and is known as the Primary Valuation.
There are decades of documents relating to this survey, some of which are just recently becoming available online, they are a rich source of information including personal details, land boundaries, land area, plans & maps
The letters commonly known as O’Donovan’s Ordnance Survey Letters, were the surveyors’ field notes, commentaries and correspondence to the Ordnance Survey headquarters in Dublin. They were written between 1834 and 1841 and are now FREELY available online on Ask About Ireland