In the 1950 case of Ackermann v. United States, the Supreme Court ruled that a petitioner could not withdraw his waiver of appeal rights after he had already served his sentence and been released from prison. The case involved two German nationals who were deported for their involvement in Nazi activities during World War II. They filed petitions to set aside their convictions but later withdrew them voluntarily, waiving their right to appeal. After serving time in prison and being released, they sought to reinstate these appeals on grounds that they were coerced into withdrawing them due to fear of further prosecution. However, the court held that there was no coercion or duress involved in their decision-making process and thus denied reinstating their appeals.

In the dissenting opinion for Ackermann v. United States, Justice Black argued that the majority's decision was a departure from established principles of justice and fairness. He contended that Mr. Ackermann should not be penalized for his lawyer’s mistake in failing to appeal within the prescribed time limit, especially given that he had been misled by government officials into believing he could later file an appeal if necessary. Furthermore, Justice Black pointed out inconsistencies in how different cases were treated; while some defendants were allowed to reopen their cases due to legal errors or newly discovered evidence even after many years had passed, Mr. Ackermann was denied this opportunity simply because his attorney missed a deadline due to misinformation provided by government officials.