http://www.nationalarchives.ie/censusrtns.html "Census Returns: A census of the Irish population was taken every 10 years from 1821 until 1911. Manuscript returns for each household survive for all 32 counties for 1901 and 1911. The returns are arranged by townland or, in urban areas, by street. The returns for each townland or street consist of: (a)Forms (Forms A) filled in by the head of each household, giving the names of all people in that household on census night and their age, occupation, religion and country of birth. (b)Forms (Forms N, B1, B2) filled in by the official taking the census, summarising the returns for that townland or street. If you wish to see the returns for a particular townland or street, you must first establish: i.the District Electoral Division number in the Townland Index for 1901 and the Supplement for 1911, or the street indexes for Belfast, Cork, Dublin, Kingstown (Dun Laoghaire) and Limerick ii.the townland or street number in the list of census returns for the year and county in question. No manuscript returns survive for 1861, 1871, 1881 and 1891. There are some returns for 1821, 1831, 1841 and 1851 covering parts of Counties Antrim, Cavan, Fermanagh, Galway, King's Co.(Offaly), Londonderry (Derry), and Meath, and there is a list of heads of household named in the returns of 1851 for Dublin City (see list of 19th century census returns). There are also census search forms for each county giving the results of searches made in the returns of 1841 and 1851 for pension purposes (see separate list for each county), and some other copies made from the returns of 1821 - 51(see list of 19th century census records - miscellaneous copies and certified copies made for pension purposes). The 1901 census of Leitrim and Roscommon is available on the web through the Leitrim-Roscommon genealogy site