In this article, I will discuss the role of the Irish in the Civil War focusing on some famous units, primarily on the Northern side but also some in the South. I will profile the three leading Irish-American military leaders of the war – Thomas Francis Meagher of the Irish Brigade, “Little” Phil Sheridan of the Union, and Patrick Cleburne of the Confederacy. While “Stonewall” Jackson was of Ulster Scots-Irish stock, I am not including him. Seven Union and six Confederate generals were Irish-born. And I will discuss the conflict between the Irish immigrants and the Negroes, which erupted in the New York City draft riots of July, 1863.