Why did Samuel Gridley Howe help found the Boston Vigilance Committee?

Samuel Gridley Howe helped found the Boston Vigilance Committee in 1846 as part of his commitment to the abolition of slavery.

He established the committee to protect fugitive slaves from Southern slave catchers and their Northern allies. By taking this action, Howe and other opponents of slavery—who identified as Conscience Whigs—sought to distance themselves from the so-called Cotton Whigs, who were sympathetic to the institution of slavery.1