Analyzing Dr. Joel Mokyr's Data
The following links contain information originally prepared by Dr. Joel Mokyr, Professor of Economics at Northwestern University about Ireland in the year 1841. This seems to to the earliest reliable data available. According to Dr. Mokyr, the 1821 census is very sparse in the information it supplies and the 1831 census data is very unreliable.
When looking at the data below in Social Indicators: by County, 1841, please note that one British Pound used as currency in 1840 Ireland was worth about five U.S. Dollars at the time.
Some information is about the size of farms. Other information is about the quality of life. Number of Farms: by County, 1841 Social Indicators: by County, 1841 Farm Size: by County, 1841
When comparing this data, remember that the average farm size in the U.S. in 1997 was 471 acres . Notice how much food the average American (including you) consumed during each of the years on the following table. What would your eating habits be like if you lived in Ireland in 1841? Why would there be a difference?

Source: U.S. Department of Agriculture. Agriculture Fact Book 1998 http://www.usda.gov/news/pubs/fbook98/content.htm