Norwegians in the Civil War

I'm currently working on a book about men from the parishes Strand, Forsand, Årdal, Fister and Hjelmeland who fought in the US Civil War. I lost all my original data a year ago, so it's back to the fact-finding phase again. I've concentrated on emigrants born between 1811 and 1847 (oldest being 50 y.o. in 1861, the youngest 18 y.o. in 1865). So far I have 618 individuals on my list. 84 are identified as having fought in the war, but I still lack 21 of these in regard to units and other specifics on their service (Being listed as war pensioners, listed with Ulvestad as Civil War vets etc.). So to get a bit further on this project: If anyone has anything whatsoever on emigrants from this area, having emigrated before 1865 that is, I'd greatly appriciate any info. This goes to both veterans and non-veterans, as I also need to sort them out, all of them. And in closing: The plan was originally to cover all of Ryfylke, but it's too much for one book. So I have plans for two more some time in the future. This one will cover "Ytre Ryfylke". The second will cover the islands, i.e Rennesøy, Finnøy and Stjernarøy. The third will cover "Indre Ryfylke", i.e. Erfjord, Jelsa, Sand, Suldal, Vikedal, Vindafjord, Nedstrand and Tysvær. Finally, I might start on Etne and Skånevik, but that's in a distant future for sure. But info on any pre-1865 emigrants from any of these parishes will also be greatly appriciated, as I've already done some basic fact-finding on all these areas along the way. Stein