There is no such thing as the 'European confederacy'.
Two different countries.
The Confederacy lost the United States Civil War.The states formed a confederacy. We joined the confederacy.
England
British textile manufacturers discovered new sources of cotton in Egypt and India. Pressure to recognize the Confederacy weakened. The United States wanted to prevent other countries like Great Britain from recognizing the Confederacy.
To gain enough credibility to encourage recognition from foreign countries.
France and Spain
The French and the English did not support the Confederacy during the Civil War. Instead, the countries decided to support the Union.
The European countries wait to help the confederacy. All because Jefferson Davis thought the cotton textile company would lead o a diplomatic recognition and mediation or military intervention.
The Museum of the Confedreracy is in Virgina.
After the Battle of Antietam, Lincoln announced the Emancipation Proclamation. This discouraged foreign governments from recognizing the Confederacy, because Lincoln had, with the proclamation, made the confederacy the poster child of slavery, and the people of the foreign countries that were considering recognizing the confederacy didn't want to be associated with the pro-slavery side of anything.
The confederacy would not use slaves as soldiers because they were afraid they would defect to the north. So they were made to dig trenches and the like during the war.