The most important military installations in Illinois are the Great Lakes Naval Training Center near Chicago and Scott Air Force Base near Belleville. Total active-duty military personnel numbered 25,036 in 2002. Illinois firms received defense contract awards amounting to $1.7 billion in 2001.
About one million Illinoisans served in World War II, of whom 30,000 were killed. There were 1,003,572 veterans of US military service in Illinois as of 2000, of whom 217,908 served in World War II; 133,155 in the Korean conflict; 289,637 during the Vietnam era; and 97,386 during 1990–2000 (including the Persian Gulf War). Veterans' benefits reached $1.6 billion in 2002.
In 2000, the Illinois State Police employed 2,089 full-time officers.