EXHIBIT 23.1 The Board of Directors UnionBancorp, Inc. Ottawa, Illinois We consent to the incorporation by reference in Registration Statement No. 333-16359 on Form S-8 of UnionBancorp, Inc. of our report dated January 23, 2004 appearing in this Annual Report on Form 10-K of UnionBancorp, Inc. for the year ended December 31, 2003. /s/ CROWE CHIZEK AND COMPANY LLC -------------------------------------------- Crowe, Chizek and Company LLC Oak Brook, Illinois March 24, 2004