England and France were on the brink of intervening and recognition several times during the war. This is mostly attributed to the skills of America's minister to England, Charles Francis Adams. If it weren't for him the outcome of the war may have greatly changed. A fun fact is Charles Francis Adams is the grandson of former President John Adams and son of former President John Quincy Adams.
During the Civil War, the Union started a blockade of Confederate ports in order to prevent the confederacy from obtaining money, weapons, or any war supplies from European nations, specifically Great Britain and France. The Union also constricted the trade of cotton between the south and Europe which destroyed any hope of the South gaining currency. This was significant because now the Union can produce more money, trade, and weapons than the Confederacy, which would give the north much more power and chance at winning the war. However, without cotton from the south, it harmed French and British textile economies and this caused frustration with the Union. Fun Fact- The Union did not realize until later that some Confederate traders could travel to Mexico or the Caribbean Islands to trade with European traders.
Charles Wilkes, a US Navy Officer, captured two confederate envoys aboard the British ship, the Trent, in Havana, Cuba. Wilkes took both Confederate messengers, Jason Mason and John Slidell, illegally off the ship. The envoys were trying to gain recognition from Great Britain and France as seperate states from the Union. GB accused the US of violating British neutrality during the Civil War and this created a diplomatic crisis between the US and GB. This event was significant because it caused the British to support the Confederacy a little more and that the Union had to release the envoys, otherwise, war could break out between GB and the Union. Fun fact- Both Mason and Slidell were accompanied by their wives and children.
Throughout the period of French intervention in Mexico, the overall U.S. policy was to avoid direct conflict with France, and voice displeasure at French interference in Mexican affairs, but ultimately to remain neutral in the conflict. After 1865, Seward provided more direct support for Juárez, while French willingness to withdraw de-escalated Franco-American tensions. Although U.S. support for Juárez improved U.S.-Mexican relations temporarily, disputes over policing of the border under Secretary of State William Evarts would diminish good relations. Fun Fact- Maximilian of Habsburg ruled both Austria and Mexico because France offered him the Mexican Empire.
During the start of the war Abraham Lincoln stated that reason for the war was to preserve the Union rather than abolish slavery. Then, thousands of slaves fled from the south to join the invading northern armies. Lincoln believed that changing the focus to slavery would be a better military strategy, as well as being the right thing to do. This was a huge step in gaining Great Britain's support as they were considered progressive towards slavery. In fact, due to the political campaigns of William Wilberforce decades earlier, England had outlawed slavery at home and in its colonies. When the civil war had become about slavery, England was unable to morally recognize the south or intervene in the war, as it would it be considered diplomatically hypocritical. An extra fun fact is that the Emancipation Proclamation did not free a single slave.
Queen Victoria issues a proclamation of neutrality stating that Great Britain would remain neutral in the domestic affairs of the United States until the end of the war. This also instructed British citizens to observe this neutrality. Although, many of the citizens ignored this and supported the confederacy as a vast majority of the Confederate Navy was built in Liverpool, England during the war using private dollar, and the port also became the unofficial location for the Confederate embassy within Great Britain. Great Britain was an important factor in the war. The main reason for Great Britain's activity in the war was for economic gains.