The Gideon v. Wainwright case, decided by the U.S. Supreme Court in 1963, significantly impacted American legal rights by establishing the constitutional right to free legal counsel for defendants who cannot afford an attorney. Prior to this ruling, states were not required to provide legal representation in criminal cases. This case emphasized the importance of fair trials and due process, reinforcing the idea that justice should be accessible to all, regardless of economic status. The decision ultimately led to the requirement that public defenders be available in state courts, greatly shaping the American legal landscape.