The Irish Brigade consisted almost entirely of Irish immigrants who were organized and under the command of BG Thomas Francis Meagher, an Irish nationalist. The Irish Brigade would suffer horrific casualty numbers in the Civil War. At Antietam ,they would lose 600 men. In front of the stonewall at Fredericksburg, they would lose another 545 men. before they advanced on Mayre’s Heights, they would attach sprigs of boxwood on their hats. At Gettysburg, they would lose a staggering 320 out of 530.The New York Draft Riots were a result of Irish immigrants refusing to serve after hearing of the losses of the Irish Brigade. By 1864, the fighting effectiveness of the brigade was reduced to just 2 regiments.