Notes written by May tell of his trip to England in the summer of 1843, wherein he attended the annual meeting of the Western Unitarian conference and gave a speech on American Unitarian churches and their attitude toward slavery. May advised that should the English Unitarians be moved to send their American brethren counsel on the subject of slavery, "it would be gladly received by many in America." May adds that subsequent to this conference, a letter dating from December of 1843 was sent by Unitarian Minsters of Great Britain and Ireland to American ministers. Signed by 185 Unitarian ministers of England, Scotland, Wales, and Ireland, the address "was a most eloquent, manly, affectionate, and in all respects Christian letter."