"Three Cheers for the Abolitionist Pope!": American Reaction to Gregory XVI's Condemnation of the Slave Trade, 1840-1860

In December, 1839, Pope Gregory XVI issued In Supremo, an apostolic letter that condemned the slave trade in the strongest possible terms. He published the statement at the prompting of the British government, which had been campaigning for years to bring the trade to an end. The British believed that a papal letter might persuade Spain and Portugal to enforce the laws against slave trafficking in their domains, but it had little impact on either country. Instead, Gregory's pronouncement set off a debate both within and without the Catholic community in the United States. During the 1840's and '50's, it twice surfaced during presidential campaigns, was hotly debated by supporters of the Irish Repeal¹ movement, and was hailed by the abolitionist leader Wendell Phillips. Even the Catholic bishops, who were very wary about making political pronouncements, were drawn into the fray. Indeed, as the Church's ranks swelled through immigration from Ireland and to a lesser extent from German states and made it America's largest religion, arguments raged over what it really taught about slavery.² All the way up until the Civil War, abolitionists repeatedly put forward Gregory's letter when trying to make the case that the Catholic Church opposed slavery while most American Catholic leaders sought to interpret it in a narrow fashion so as to minimize its significance.

Enlisting the Pope

In the 1830's, the British government was on a crusade to suppress the African slave trade.³ The British and the Americans had both outlawed the practice in 1807, and France had followed suit in 1818.⁴ At the Congress of Vienna in 1815, the British had persuaded the other powers to sign a declaration against the slave trade, but it was vague and nonbinding.⁵ They then negotiated separate treaties with Spain and Portugal in an effort to suppress it. By 1838 Lord Palmerston, the British foreign secretary, was growing impatient. Slaves were still being shipped by the thousands from Africa to Cuba and Brazil.⁶ Consequently, he looked to the United States and to the Papacy for help. He contacted the American ambassador to the Court of St. James, Andrew Stevenson, to see if the United States might be interested in sponsoring a worldwide conference on the slave trade. Stevenson, a Virginia slaveholder, was not enthusiastic, but he duly passed on the proposal to the American Secretary of State, John Forsyth, a Georgian, who was deeply suspicious of anything that smacked of abolition.⁷ Although opposed at least in theory to the slave trade, Forsyth was not about to devote American resources to such a project.

Palmerston had more reason for optimism with regard to the Papacy. In 1815 Pope Pius VII had issued a brief condemning the slave trade in response to an appeal from the British foreign secretary, Lord Castlereagh.⁸ In July, 1839, Thomas Aubin, the British consul at Florence, wrote to the pope's secretary of state, Cardinal Luigi Lambruschini, asking for a declaration from the Holy See. Aubin noted that the British had been working for years to suppress the trade. While most European countries had willingly co-operated with them, the British had trouble with certain countries which were "in spiritual communion with the Holy See."⁹ Aubin was sure that a public declaration on this subject by the pope would be "most advantageous to the cause of humanity and would render a great honor to the Roman government."¹⁰

When Gregory learned of Aubin's letter, he decided to put the matter before the cardinals who served in the Congregation for Extraordinary Ecclesiastical Affairs.¹¹ Before being elected pope in 1831, Gregory had served for six years as prefect of Propaganda Fide, the curial congregation that oversaw Catholic missions all over...