Final answer:
British and French ruling classes initially showed support toward the Confederacy mainly to weaken the Union and maintain access to the South's cotton, crucial for their textile industries. However, Britain's reluctance to risk war with the Union and the moral stance on slavery led to the decline in support.
Step-by-step explanation:
The most important factors in the support initially shown the Confederacy by the ruling classes of England and France were their desire to weaken the Union and to maintain access to an important commercial rival in the form of the South. The ruling classes believed that supporting the Confederacy could lead to the disruption of the Union's economic and political power, while also ensuring the continued flow of the South's cotton, which was crucial for European textile industries.
The Southern states were a near monopoly supplier of cotton, which was the raw material for British and French textile mills. The Confederacy hoped to use this dependence to gain support. Great Britain and France showed initial interest due to this, as they required the raw materials for their industries. However, Britain did not wish to risk war with the Union, which would affect their grain imports and consumer goods market.
Moreover, the moral issue of slavery and the Union's Emancipation Proclamation made supporting the Confederacy less appealing for the British, who had abolished slavery in 1833. Ultimately, both Britain and France found alternative cotton suppliers and refrained from aligning with the Confederacy, which hoped for formal recognition or an alliance.