I'm not sure if this is the best place to ask this so, mods, please feel free to delete this if it's against the rules.
I'm starting to gather sources for my honors thesis, which centers around the Italian-American community in St. Louis. For the background information portion, I want to paint a picture of life in post-Risorgimento Italy as well as get some information on how the Italian government reacted to immigration to the United States. I'm also interested in general immigration/conscription records. Google searches have been pretty fruitless thus far, so I'm hoping that someone will know of some primary sources online in Italian!
TIA.
If what you are lookig for is raw data (and you understand Italian as your question suggests), here you can find a (not very organized) digitalization of publications of the Italian Institute of Statistics (and its previous incarnations) dating back to 1861 and some earlier works.
I's suggest you start from the "Annuario statistico Italiano" voice. Those include somewhat detailed chapters on the state of the Army and Navy as well as a general discussion of the population overview.
A word of advice though: data are extremely difficult to fit together, as observations, record handling and stats collecting changed over time in a way that is not always easy to grasp from the brief introductory statements.
The "Annali" section covers some more specific topics (it's basically a "journal of statistcs" of the institute) and I would check there is some of those discusses the issue of emigration - this would include some elaboration on the statistics, so that the results would be more reliable and immediately usable for your work.
Also, this is the official site of the Institute of Statistics. I sort of hate it, because I am never able to find what I am looking for, but they may have some more recent publication available online. And consider as well the publications of the National Bank of Italy, that may provide free materials on the economic history of post unitary Italy - check for the publications of G. Toniolo for instance or the older works of S. Fenoaltea (they both did research with the National Bank).