Clancy's arrival in Charleston was delayed to a severe illness. Upon recovering, he visited family and friends in Cork and Carlow, and attempted to recruit priests and seminarians for Charleston. A personal reluctance also factored into his delay: "If there is any other place where the knowledge of philosophy and theology and the faculty of preaching in English would rebound to the glory of God . If however the Holy Father insists I shall go with an heavy heart." He finally arrived in Charleston in November 1835. After a few months' dissatisfied sojourn, Clancy requested a transfer to another field. He claimed there was an insufficient amount of work to be done, and Bishop England wrote to Rome: "He is very distinguished for his character, zeal and piety, but in one year he has wrecked that whole constitutional system of church government which has taken me years to perfect." He attended the Third Provincial Council of Baltimore in 1837, and in July of that year was translated to the see of Demerara, British Guiana as Vicar Apostolic of British Guiana.
Washington Irving
In 1837, a Protestant lady brought to Clancy's attention a passage in The Crayon Miscellany, and questioned whether it accurately reflected Catholic teaching or practice. The passage under "Newstead Abbey" read:
One of the parchment scrolls thus discovered, throws rather an awkward life upon the kind of life led by the friars of Newstead. It is an indulgence granted to them for a certain number of months, in which a plenary pardon is assured in advance for all kinds of crimes, among which, several of the most gross and sensual are specifically mentioned, and the weaknesses of the flesh to which they were prone.
Clancy wrote Irving, who "...promptly aided the investigation into the truth, and promised to correct in future editions the misrepresentation complained of...." Clancy traveled to his new posting by way of England, and bearing a letter of introduction from Irving, stopped at Newstead Abbey and was able to view the document to which Irving had alluded. Upon inspection, Clancy discovered that the document was not any sort of indulgence issued to the friars from any ecclesiastical authority, but a pardon given by the king to some parties suspected of having broken "forest laws". Clancy requested the local pastor to forward his findings to Catholic periodicals in England, and upon publication, forward a copy to Irving. Whether this was done is not clear as the disputed text remains in the 1849 edition.
British Guiana
Clancy recruited clergy from Italy, Austria, England and his native Ireland, also introducing the Presentation Sisters. He resigned as Vicar Apostolic on September 3, 1843. Retiring to Ireland, he died at Cork less than four years later, aged 45.
