Why were both the French and British governments sympathetic to the Confederacy during the Civil War?

There was considerable sympathy among wealthy Britons for the Confederacy, but generally the working classes favored the Union in the conflict, as did much of the liberal middle class, which was strongly anti-slavery. The French and British governments, especially Prime Minister Lord Palmerston, were not all that sympathetic to the Confederacy, at least not enough to justify intervention in the Civil War. Rather, at the beginning of the war both governments calculated that their economic...

There was considerable sympathy among wealthy Britons for the Confederacy, but generally the working classes favored the Union in the conflict, as did much of the liberal middle class, which was strongly anti-slavery. The French and British governments, especially Prime Minister Lord Palmerston, were not all that sympathetic to the Confederacy, at least not enough to justify intervention in the Civil War. Rather, at the beginning of the war both governments calculated that their economic and strategic interests might be aligned with those of the South. Both the British and the French had developed a thriving industry in textiles, and they depended on Southern cotton to keep the mills running. For this reason, the Union blockade, some thought, would be ruinous to the economies of these nations. Dire predictions of a "cotton famine" never materialized, however, largely because there had been a glut of cotton in the years preceding the war, and because Great Britain was able to turn to India and Egypt for cotton. Generally, France was following Great Britain's lead, and while there were a few diplomatic crises (the Trent affair, in particular) the British government generally kept out of the conflict. The Emancipation Proclamation, promulgated in 1863, redefined the conflict as a struggle to destroy slavery as well as preserving the Union. After this, there was little chance that either government would intervene in the war.