July 1-3- The Battle of Gettysburg, Pennsylvania. The bloodiest battle of the Civil War dashes Robert E. Lee's hopes for a successful invasion of the North. July 4- Vicksburg, Mississippi, surrenders to the Union Army under Grant.
Method. 1  Test the pen to make sure it can tell the difference between good money and computer paper. 2  Apply spray starch to the next dollar bill in an attempt to make it read as fake. 3  After drying, test the results by re-applying the counterfeit money detector pen to both the dollar and to the computer paper.
Of the two $20 bills shown, one of them is fake. Can you tell which? For its latest investigation, ABC News' 20/20? caught up with a master counterfeiter who says he taught himself how to make fake U.S. currency and printed $20 bills that were virtually undetectable-millions of dollars-worth.