On August 17, 1998, President Bill Clinton becomes the first sitting president to testify before the Office of Independent Counsel as the subject of a grand-jury investigation. The testimony came after a four-year investigation into Clinton and his wife Hillary’s alleged involvement in several scandals, including accusations of sexual harassment, potentially illegal real-estate deals and suspected “cronyism” involved in the firing of White House travel-agency personnel. The independent prosecutor, Kenneth Starr, then uncovered an affair between Clinton and a White House intern named Monica Lewinsky. When questioned about the affair, Clinton denied it, which led Starr to charge the president...