In June 1840, English abolitionist Thomas Clarkson was the key speaker at the first World Anti-Slavery Convention held in London. The convention was sponsored by the British and Foreign Anti-Slavery Society, which had been formed the previous year. This letter written by Clarkson in July 1840 to the Society and addressed to Joseph Sturge expresses Clarkson's thanks for the kindness shown him while in London. Clarkson comments that despite his age and infirmities, “you may count upon my services hereafter if I can be made useful to you in any way” in “promoting the good cause.”