Tom, as you know there were 10 Louisiana Infantry Regiments at Gettysburg, and they formed the brigades of Nicholls' and Hays' both under Ewell's Corps. Hays' brigade is going to have a higher number of prisoners and of those prisoners being desirous in joining the Union Army more than 50% were of foreign birth or Northern birth at least at this stage of the research of Gettysburg. I believe that the number used in previous threads of 3.5% of the number of foreign births with the ANV at Gettysburg is going to be slightly higher based from what I have saw so far. You are correct I believe about New Orleans after all it was the largest city in the South. Louisiana it appears, has more Irish and German births compared to Virginia as an example whose has more Irish and English births. I am a little surprised in the number of Northern births thus far at Gettysburg who fought for the South. N.Y., PA. MA, and Maine seem to be the most prevalent thus far.