What issue did Samuel Slater's letter to Mr. Benchley highlight?

Samuel Slater's letter to Mr. Benchley highlighted concerns regarding the competition and challenges faced by American manufacturers, particularly in the textile industry. He emphasized the need for support and protection for domestic industries against foreign competition, as well as the importance of innovation and investment in technology to improve productivity. Slater's insights underscored the broader economic issues of the time, including the balance between free trade and the protection of emerging American industries.