The expansion of civil rights for Black Americans was a crucial driver of the South’s political realignment with a national conservative movement. As early as 1948, Southern opposition to civil rights, fueled by President Harry Truman’s civil rights agenda, created the first cracks in the “Solid South.” Of the three major civil rights legislative initiatives in 1948, the anti-lynching bill has remained the most unstudied and underappreciated by historians as compared to its anti-poll tax and anti-employment discrimination counterparts. This thesis examines the proposed federal anti-lynching law within the contentious presidential election of 1948 and the period of heightened awareness and support for civil rights following the Second World War. This history utilized the archives of national newspapers, the NAACP, and the legislation’s Southern congressional opponents to analyze the Republican campaign to make anti-lynching legislation federal law as well as the Southern congressmen’s rhetorical and practical strategies, which resulted in the defeat of the anti-lynching bill. The 1948 anti-lynching bill revealed the legislative power of Southern congressmen, exposed the limits of the Republican commitment to civil rights, and catalyzed Southern demand for an alternative, conservative political faction. The 1948 anti-lynching bill and postwar federal support for civil rights more generally provide a compelling case to more closely consider 1948 as a moment of significant partisan realignment in American political history.