In 1784, he was a member of the committee appointed to act upon the definitive treaty with Great Britain. He was also upon the one for defining the power of the board of the treasury, the one upon foreign relations, and the one upon the war office. The next year he closed his congressional course, and, as the crowning glory of his arduous and protracted labours in the national legislature, he advocated with great zeal, forensic eloquence, and powerful logic the resolution of Mr. King for abolishing slavery in the United States. His whole force of mind was brought to bear upon this subject and added a fresh lustre to the substantial fame he had long enjoyed. He then retired to his now peaceful home, to repair the wreck of his fortune and enjoy the blessings of that liberty for which he had so ardently contended. In the spring of 1786, he was appointed by Congress a commissioner of the national loan office for Rhode Island, and shortly after, he was elected to the seat of chief justice of the supreme court of his native state. Upon the organization of the federal government under the constitution, President Washington appointed him collector of customs for Newport, which station he ably filled until he took his tranquil departure to another and a brighter world. The evening of his life was as calm and mellow as an Italian sunset. Esteemed by all, he enjoyed a delightful intercourse with a large circle of friends. Honest, punctual and circumspect, he enjoyed the confidence of the commercial community in his official station, as well as the approbation of all in the private walks of life. During the thirty years he was collector of customs, a loss of only two hundred dollars upon bond accrued to government, and upon that bond he had taken five sureties.