Cotton was unique; it maintained a clout that slave-produced sugar never commanded. The British anti-slavery organization, the Society of Friends, had employed a boycott of sugar in its assault on slave-grown West Indian sugar. In the 1790s an estimated 400,000 British boycotted this sugar, and sugar imports from Indian increased. But the gesture had a negligible impact on the sugar plantations. Even a symbolic boycott or attack on American slave-produced cotton was impossible. American cotton was far more difficult to replace than sugar grown by slaves thousands of miles from Britain.

Britain, aware of its precarious dependency on American slave-grown cotton, was not concerned about. American slavery, it feared a civil war or crop failure in America, which might be devastating. In 1858 the Lancashire mills established the Cotton Supply Association, with the specific purpose of diversifying sources for cotton to India, Egypt, and Brazil.