The National Archives has a record of all military in the Civil War. I found 2 records requesting pensions. They had to list the place of birth, usually town and county and country, all children of the marriage,living and deceased, with dates of birth and death .Complete transcript of their service. Addresses.Also the Naturalization records in certain states lists place of birth and dates. MA has the best records that I found. They go back pretty far.Also lists those who recommend them for citizenship.Date of immigration on census, with a 5 year waiting period, could give the clue to year of naturalization. If you can get to DC, you can actually get the file and copy it.I located the naturalization of several ancestors in Albany NY and it shows the county of origin.MA gave town.Some counties changed names. I found many Irish put Ireland on their tombstones, some added town and Co, but not many did. Depended on their circumstances. Kathleen S.