 On 4 August 1909 , Illinois was decommissioned in Boston . The ship then underwent a major modernization , receiving new " cage " masts and more modern equipment . She spent the next three years in active service with the fleet , before being decommissioned once more on 16 April 1912 . She returned to service on 2 November for major training maneuvers with the Atlantic Fleet . Illinois made training cruises to Europe with <unk> from the US Naval Academy in mid @-@ 1913 and 1914 . By 1919 , she had been decommissioned at the Philadelphia Navy Yard . On 23 October 1921 , she was loaned to the New York Naval Militia for training purposes . The 1922 Washington Naval Treaty , which mandated significant reductions in naval strength , stipulated that Illinois must be rendered incapable of <unk> action . As a result , she was converted into a floating armory at the New York Navy Yard in 1924 and was assigned to the New York Naval Reserve . 
