In the 1966 case of Entsminger v. Iowa, the United States Supreme Court ruled in favor of a prisoner who had been denied his right to appeal due to an inadequate legal brief provided by his court-appointed attorney. The defendant, Mr. Entsminger, was convicted for breaking and entering and sentenced to ten years imprisonment by an Iowa state court. His lawyer filed a brief on appeal that failed to cite any authority or make any argument for reversal which led the State Supreme Court dismissing it as frivolous without examining its merits. The U.S. Supreme Court held that this action violated Entsminger's constitutional rights under the Fourteenth Amendment's Due Process Clause since he was not given meaningful access to justice through effective assistance of counsel during his first appeal as-of-right from conviction. This ruling emphasized that states have an obligation under federal law not only provide indigent defendants with attorneys but also ensure those attorneys are providing adequate representation in criminal appeals.

In the dissenting opinion for Entsminger v. Iowa, Justice Harlan disagreed with the majority's decision to reverse and remand the case back to state court. He argued that there was no constitutional violation in this case as he believed that a defendant does not have an absolute right to counsel on appeal under Douglas v. California, 372 U.S. 353 (1963). Instead, he contended that such a right only exists when an appellate review is provided by law or guaranteed by constitution - neither of which applied in this particular instance since Iowa had discretionary review procedures at the time of Mr.Entsminger’s trial and conviction. Furthermore, Justice Harlan pointed out that even if there were any error made during trial proceedings it would be harmless beyond reasonable doubt given overwhelming evidence against Mr.Entsminger including his own confession.