The abettors of slavery, in the course of their defence of the system, maintained that only such negroes as were captured in battle were sold as slaves, and, if not so sold, then they were reserved for a still more frightful doom in their own country. Clarkson knew of the slave-hunts conducted by the slave-traders, but had no witnesses to prove it. Where was one to be found? Accidentally, a gentleman whom he met on one of his journeys informed him of a young sailor, in whose company he had been about a year before, who had been actually engaged in one of such slave-hunting expeditions. The gentleman did not know his name, and could but indefinitely describe his person, He did not know where he was, further than that he belonged to a ship of war in ordinary, but at what port he could not tell. With this mere glimmering of information, Clarkson determined to produce this man as a witness. He visited personally all the seaport towns where ships in ordinary lay; boarded and examined every ship without success, until he came to the very last port, and found the young man, his prize, in the very last ship that remained to be visited. The young man proved to be one of his most valuable and effective witnesses.
During several years Clarkson conducted a correspondence with upwards of four hundred persons, travelling more than thirty-five thousand miles during the same time in search of evidence. He was at length disabled and exhausted by illness, brought on by his continuous exertions: but he was not borne from the field until his zeal had fully awakened the public mind, and excited the ardent sympathies of all good men on behalf of the slave.
