The <a href="https://en.wikipedia.org/wiki/Supreme_Court_of_the_United_States" id="mwfQ" rel="mw:WikiLink" title="Supreme Court of the United States">U.S. Supreme Court</a> hands down its decision in <i id="mwfg"><a href="https://en.wikipedia.org/wiki/Guinn_v._United_States" id="mwfw" rel="mw:WikiLink" title="Guinn v. United States">Guinn v. United States</a></i> 238 US 347 1915, striking down <a href="https://en.wikipedia.org/wiki/Oklahoma" id="mwgA" rel="mw:WikiLink" title="Oklahoma">Oklahoma</a> <a href="https://en.wikipedia.org/wiki/Grandfather_clause" id="mwgQ" rel="mw:WikiLink" title="Grandfather clause">grandfather clause</a> legislation which had the effect of denying the right to vote to blacks.