In concert with the traditional diplomacy practiced by Charles Francis Adams, Secretary of State Seward authorized a massive covert campaign in Europe to deny the Confederacy the support it desperately needed for secession to succeed. The point man for this clandestine campaign was Henry Shelton Sanford, the American ambassador to Belgium. Sanford’s duties in Brussels represented only a small portion of his work on behalf of the Union because Secretary Seward had authorized him to travel anywhere throughout Europe to counter Confederate agents.
His diplomatic status permitted Sanford to travel unimpeded, and he spent a considerable amount of time in Paris and London, where he created a sophisticated espionage system. In Britain he hired a police detective who had a force of private detectives at his disposal who dispersed throughout the country to monitor the major ports and manufacturing centers where Confederate agents were signing secret contracts for blockade runners. Sanford’s operatives also penetrated the British postal service and paid postmen to supply information on correspondence to and from Confederate agents. Telegraph offices were infiltrated for purposes of intercepting or altering messages from enemy agents. Clerks in various manufacturing centers were bribed to hand over documents related to Confederate contracts, and sabotage was occasionally employed to disable ships being constructed for the Confederacy. As Sanford wryly noted in a letter to Secretary Seward, “accidents are numerous in the [English] channel you know.”
Sanford eventually constructed a network that reached into Belgium, France, Spain, Italy, and Prussia, and had a $1 million slush fund at his disposal. The most ambitious element of Sanford’s campaign was a propaganda effort to sway European public opinion in favor of the Union. Sanford bribed journalists and their editors to tilt their coverage in favor of the Union cause, and at one point even attempted to buy a Belgian newspaper. Priests and pastors were targeted as well, and prominent American clerics were dispatched to Europe to plead with their brethren to deny the Confederacy the support it sought. Labor unions were a high priority in Britain, where arguments made on behalf of the dignity of free labor and the indignity of chattel slavery resonated with the working class. Sanford’s operatives organized “spontaneous” antislavery rallies, and this issue, perhaps more than any other, proved impossible for Confederate operatives to overcome.
Henry Shelton Sanford’s agents went to extraordinary lengths to deny the Confederacy weapons, markets, and diplomatic backing. In some ways the outcome of Sanford’s covert struggle was as important as what took place on the battlefields of the United States. If the South had succeeded in securing the political and economic support of the European powers, the Confederacy might well have won the war.
In this letter written from Belgium early in his campaign, Shelton urged Secretary Seward to convince Congress to provide more funds for the “secret service” and revealed some of the tactics he planned to employ to spy on a Confederate envoy.