The 1st Illinois Cavalry and the 1st, 3rd, and 5th Illinois Infantry regiments were trained at Camp G.H. Thomas in Chickamauga Park, Georgia. The 2nd and 4th Illinois Infantry regiments received the bulk of their training at Camp Cuba Libre in Jacksonville, Florida. The 6th and 7th Illinois Infantry regiments were stationed at Camp Russell A. Alger, Virginia, near Washington, D.C.
Camp life was often unbearable. The men slept in leaky tents which caused their clothes and belongings to remain soaked for days at a time. Poor sanitation, swampy campsites and spoiled food caused many of the men to suffer from diseases such as dysentery, malaria and typhoid. Soldiers attempted to combat this invisible enemy through good personal hygiene and diet. Another shortfall was the uniforms and equipment issued to the soldiers. Instead of the modern bolt-action Springfield Krag-Jorgensen rifle, Illinois troops were issued the outdated Springfield "Trapdoor" rifle. Similarly, while the pattern 1898 khaki uniform was issued to regular troops, Illinois soldiers continued to wear a woolen uniform, inappropriate for the tropical environment of Cuba and Puerto Rico.
Of the Illinois troops serving in the war, elements of the 1st, 3rd, and 6th Illinois Infantry regiments were the only units to see actual combat. The following account was recorded by a soldier of the 1st Infantry.
''Toward dawn, they quietly and calmly opened fire upon the Spanish trenches opposite, just to let the Spaniards know that they were wide awake and vigilant. . . The Illinois people stoutly asserted that in the gray of the morning they had seen the Spaniards creeping out of their trenches, and sneaking up the hill toward them, with the evident intention of rushing their position . . . The Illinois regiment always grew feverish for the fray during the dark hour just before dawn, and a staff officer was generally detailed to sit with them, and keeping his fingers upon the regimental pulse, try also to have them keep the peace and respect the truce.''
1 Source: National Park
Service, Soldiers and Sailors System; "A Compendium of the War of the Rebellion" by Frederick H. Dyer,Cosmas; An Army for Empire : The United States Army in the Spanish American War by A. Graham, (Shippensburg, PA: White Mane Publishing Co., 1993).