The essay argues that the views of Alexander von Humboldt - the revered representative of Enlightenment and humanitarian thought, and a transatlantic intellectual who closely observed, and commented upon, developments in American society and politics - were used by the growing Republican party in the latter half of the 1850s to win the German-American vote. Humboldt had consistently condemned the institution of slavery, and warned against its expansion into new territories. He held in high esteem John Frémont as an explorer of the West and first presidential candidate for the Republican Party. Although the German immigrant community was generally indifferent to the issue of slavery, it did share the Republicans' ideology of free soil and free labor. As Humboldt was recognized as an authoritative voice among German immigrants, his criticism of the peculiar institution, shared by many German refugee intellectuals, like Francis Lieber, contributed to the German-American community's political realignment.