In the face of abolitionist pressure and the organization of the new Republican Party, President James Buchanan and Chief Justice of the Supreme Court Roger Taney moved to resolve the questions of race and slavery in America in the years before the Civil War. Buchanan, a northern Democrat, attempted to appease pro-slavery southerners who vociferously demanded control of federal slavery policy. Taney struck another blow for white supremacy in the Dred Scott decision. Announced just days before Buchanan took office, Taney's verdict denied the petition of the slave Dred Scott, whose master had transported him from Missouri into Illinois and later Minnesota. Scott claimed that he had become free once he reached free territory. But Taney argued that African-Americans like Scott could not sue for their freedom because blacks could not be American citizens. Furthermore, individual states and territories could not prohibit slavery within their borders. Buchanan and Taney's actions elicited howls of protest among northern abolitionists, and served to galvanize moderates like Abraham Lincoln to action. Regardless of their real intentions, the President and the Chief Justice of the Supreme Court seemed to be moving in tandem to secure slavery's future in the United States. Such appearances fueled northerners' political fears of the southern "slave power," and boosted the Republican Party to rapid prominence as the vehicle of their fears.