Final answer:
The South thought Britain would support them due to reliance on cotton for their textile industry, but Britain found other sources and had political reasons to remain neutral post-Emancipation Proclamation.
Step-by-step explanation:
The idea that Britain would support the South during the American Civil War due to its reliance on cotton for the textile industry is associated with the cotton monopoly that existed at that time. In 1860, the eve of the Civil War, the Southern states of the U.S. were the primary suppliers of cotton to Britain, essential for its industrial textile mills.
The South's strategy for gaining independence included leveraging this monopoly, believing that Britain's dependency on Southern cotton for their textile industry would lead to Britain diplomatically recognizing the Confederate States of America. However, this wager failed as Britain found alternative cotton sources from India, Egypt, and Brazil and had to consider the political implications following the Emancipation Proclamation issued by President Lincoln.