The barely more refined number - 30,000-50,000 - in the piece itself, put forward by the president of America's largest anti-slavery organization, is an example of the article's rhetorical problems.

He sat on the executive committee of Boston's first vigilance committee, an anti-slavery organization devoted to assisting escaped slaves first established in 1846.

In Springfield, in response to the Fugitive Slave Act, John Brown founded his first militant anti-slavery organization, The League of Gileadites.

Come-outers themselves split further into those, like Garrison, were against any institution at all, and those who believed that political systems and churches could be reformed into anti-slavery organizations.

But anti-slavery organisations say thousands of people still live in subjugation.

The historiography of the American Colonization Society is defined by a theme of swinging between historians interpreting the Society as either a pro-slavery or anti-slavery organization.

It was the first anti-slavery organization in Michigan.

Now, as anti-slavery organizations try to purchase freedom for slaves, some critics fear that they may be inadvertently encouraging slave raids.

The Pennsylvania Abolition (or Abolitionist) Society, which had members and leaders of both races, became a model for anti-slavery organizations in other states during the antebellum years.

In 1836 Davis sat on a special committee formed to consider legislative responses to a flood of allegedly inflammatory abolitionist materials being sent into southern slave states from northern anti-slavery organizations.