Adams v. United States ex rel. McCann
In Adams v. United States ex rel. McCann (1942) 317 U.S. 269, a defendant charged with several counts of mail fraud elected to represent himself notwithstanding the court's strong advisement against such a course of action. Reinforcing the principle that a court may not compel an attorney upon an accused the appellate court affirmed the right of the defendant to exercise his informed judgment not to utilize counsel.
The court indicated not that a specific advisement must be given, rather, that the decision to waive counsel must be with "eyes open".