Before one presumes to know what antebellum immigrants were thinking it might be wise to have some actual evidence- letters, diaries. Statistics showing where immigrants lived in 1860 do not suffice. They are influenced by multiple factors, including the existence of passenger service from particular European ports to particular American ports. It also overlooks the freedom of movement Americans enjoy. This freedom of movement was especially available in northern states which had a more extensive rail, canal and river systems leading to the interior.
The north also had more industry, so that immigrants could find ready, immediate industrial employment. The south, meanwhile, offered few employment opportunities in industry or agriculture. The plantation economy was booming using slave labor; no need to actually pay an immigrant. Meanwhile, there was plenty of rich farmland available in the interior- Ohio, Indiana, Illinois, Wisconsin, Michigan, Minnesota- for those wanting to satisfy the human need to 'be one's own boss'.
I agree the statistics show the makeup of our country in 1860, and are both useful and interesting. But- like all statistics- it is dangerous to read into them what we may want them to mean.
Hi William. The most recent scholarly study of Irish participation in the Confederate forces is The Green and the Gray by David Gleeson.
Here is a link: