In 1861, after the outbreak of the
American Civil War, Eads was called to Washington at the prompting of his friend, Attorney General
Edward Bates, to consult on the defense of the Mississippi River. Soon afterward, he was contracted to construct the
City-class ironclads for the
United States Navy, and produced seven such ships within five months:
St. Louis,
Cairo,
Carondelet, ,
Louisville,
Mound City, and
Pittsburgh. He also converted the river steamer
New Era into the ironclad
Essex. The river ironclads were a vital element in the highly successful Federal offensive into Tennessee, Kentucky and upper Mississippi (February–June, 1862). Eads corresponded frequently with Navy officers of the Western Flotilla, and used their "combat lessons learned" to improve vessels during post-combat repairs, and incorporate improvements into succeeding generations of gunboats. By the end of the war he would build more than 30 river ironclads. The last were so hardy that the Navy sent them into service in the
Gulf of Mexico, where they supported the successful Federal attack on the Confederate port city of Mobile. All senior officers in the Western Theater, including Grant and Sherman, agreed that Eads and his vessels had been vital to early victory in the West. The first four gunboats were built at the Eads' Union Marine Works in
Carondelet, Missouri. The next three were built under Eads' contract at the
Mound City (Illinois) Marine Railway and Shipyard. Eads' vessels were the first United States ironclads to enter combat. On January 11, 1862 the Eads-built ironclads
St. Louis and
Essex fought the Confederate gunboats
CSS General Polk,
CSS Ivy, and
CSS Jackson at Lucas Bend, on the Mississippi River. Subsequently, on February 6, 1862, Eads' ironclads captured
Fort Henry on the
Tennessee River. This was over a month before the combat actions of the ironclads
CSS Virginia and
USS Monitor during the March 8–9, 1862
Battle of Hampton Roads. During the war, Eads wrote a check to the War Department for $1,000 to help homeless Confederates and Union sympathizers. After the war, he held a fair to raise money for the thousands of homeless refugees in St. Louis. ==Mississippi River bridge==