Immigrants were not immune from Civil War service. Indeed, many immigrants enlisted in the military as they disembarked from their ships at Castle Garden, New York often motivated by the following factors: Immigrants tended to greatly favor the Union side of the war (unless they had been living in the South for several years). Any able-bodied young man could serve. Naturalization, or native birth, was not a requirement. It was easier to be naturalized after service. There was a cash bounty for all recruits–more for those with military experience. (The illustration shown here depicts the recruiters at Castle Garden signing up German, Irish, and other immigrants with a $600 bounty incentive.) Therefore, if your immigrant, or his brother, uncle, father or cousin, was born between 1830 and 1845 (especially about 1840), you should check for Civil War military service.