That second stroke was his "Thoughts on African Colonization," published in the summer succeeding the formation of the New England Anti-Slavery Society.
Garrison's championship of the cause of the slave had started with strong faith in the efficacy and disinterestedness of the colonization scheme as an instrument of emancipation.

It commanded, therefore, his early support.

In his Park Street Church address he evinced himself in earnest sympathy with the friends of colonization.

But after his arrival in Baltimore a change began to exhibit itself in this regard.

He began to qualify his confidence in its utility; began to discern in it influences calculated to retard general emancipation.