Final answer:
Key West was important to American cigar makers due to its proximity to Cuba, facilitating access to tobacco and expertise, and was bolstered by historic US-Cuban relations post-independence.
Step-by-step explanation:
Key West was an important city for American cigar makers primarily because it was the closest American city to Cuba. With Cuba's established cigar industry and the high demand for Cuban tobacco, proximity to Cuba allowed for easy access to both materials and labor expertise. Additionally, following the Cuban War of Independence, the Platt Amendment and the US intervention in Cuban affairs, American businesses, including those in the cigar-making industry, had substantial influence and interests in Cuba. This led to Key West becoming a significant hub in the cigar manufacturing industry due to its geographic advantage and the historical context of American-Cuban relations.