Go to Cheetah (formerly CCH Intelliconnect).

• From the Cheetah homepage, use the Practice Areas box to select Securities - Federal & International.
• Scroll down until the Capital Changes box is visible, then select Worthless Securities. 
• You can view an alphabetical list or search by company name.

You could also search through All Content by keyword, for example, capital histories AND xerox to find a specific instance of interest.

 Also see Old Stock and Bond Certificates (SEC).