First Illinois Troops In Service – On Expedition To Cairo.

CHICAGO LIGHT ARTILLERY COMPANY. – Organized April 21. Discharged May 2, 1861.

LOCKPORT ARTILLERY COMPANY. – Organized April 22. Discharged July 31, 1861.

CHICAGO ZOUAVES, COMPANY "A." – Organized April 19. Discharged May 3, 1861.

CHICAGO ZOUAVES, COMPANY "B." – Organized April 15. Discharged April 29, 1861.

CHICAGO LIGHT INFANTRY COMPANY.--Organized April 19. Discharged May 3, 1861.

TURNER UNION CADETS. – Organized April 15. Discharged April 29, 1861.

LINCOLN RIFLES. – Organized April 15. Discharged April 29, 1861.

LIGHT ARTILLERY COMPANY. – Organized April 21. Discharged April 29, 1861.

HOUGHTAILING'S OTTAWA COMPANY. – Organized April 18, (Co, "F," 110th Illinois Infantry. 3 Mos.)

CAIRO SANDWICH COMPANY. – Organized April 19. (Co. "C," 10th Illinois Infantry. 3 Mos.) Participating in Swift's Cairo Expedition, April 21-29, 1861.

SOURCE: Frederick H. Dyer, A Compendium of the War of the Rebellion, Part 3, p. 1103