Using hermeneutic analyses of compositions Felix Mendelssohn wrote during the 1840s as points of departure, this dissertation depicts him as a cultural figure who used music to both underwrite and transform the state and identity politics of Restoration-era Prussia and, more broadly, German-speaking Europe. Four musical case studies point to diverse facets of this sociopolitical engagement, contextualizing it within contemporary Prussian politics and the history of German-speaking Jewry. In Chapter 2, a Sir Walter Scott-inflected examination of the narrative of the Scottish Symphony sheds light on Mendelssohn’s investment in a “politics of reconciliation,” a state-sponsored discourse that advocated the integration of minority groups into Prussian modernity through the historicization of difference. In Chapter 3, a Ludwig Tieck-informed hearing of the incidental music to A Midsummer Night’s Dream reveals an effort at state-sponsored cultural appropriation that both glorified and critiqued the Prussian monarchical order. In Chapter 4, comparison of Mendelssohn’s Prussian sacred music with the work of contemporary plastic artists August Reichensperger and Philipp Veit suggests that the composer’s use of historical “Catholic” styles was intended as a form of engagement in nationalist politics, both Prussian and pan-German. In Chapter 5, a rehearing of the opening Allegro of the Violin Concerto is used as a metaphor for the leadership role that Mendelssohn assumed in developing a “German” musical canon, building “German” musical institutions, and assimilating Jewish musicians into “German” musical life. The dissertation concludes, in Chapter 6, with a brief look at Weimar-era anti-Semitic and philo-Semitic reactions to Mendelssohn’s oeuvre, an exploration intended to emphasize the sociopolitical stakes of discourse about music and to invite further research on Mendelssohn reception.