Joseph Leech, businessman and soldier, was living in New Bern by 1758, when he was an executor of the will of his father-in-law, Frederick Jones. A wealthy landowner, he had rental property, a tannery, and other business interests. While a member of the colonial Assembly from 1761 to 1765, he served on numerous committees and introduced a number of bills. One of the latter, ratified on 6 Mar. 1764, established the New Bern Academy , a significant educational institution in North Carolina for many years taught by Thomas Thomlinson . Leech was one of its trustees.
During the Regulator  troubles, Leech was a colonel of militia and his troops were called out to protect New Bern, the capital. When a spectator attempted to get his companions to throw eggs at an officer carrying out a court-martial sentence of 150 lashes for a militiaman charged with trying to breed mutiny, Leech put the bystander under guard and "Drawing his Sword, he declared he would punish with his own Hand any person that dared to insult the Fellow merely for executing a Duty he was put on by the Court Martial; which spirited Behaviour of the Colonel caused a profound Silence, and gave general Satisfaction to the numerous Company met on the Occasion, and must also reflect great Honour to his Conduct." Leech also saw active duty at the Battle of Alamance in the 1771 campaign of Governor William Tryon  against the Regulators.
Leech was a delegate to the First, Second, and Third Provincial Congress  (1774–75), as well as a member of the Council of State  for four consecutive terms between 1776 and 1779 and again for three terms between 1784 and 1786. He was president of the council in 1778 and 1779. He also was a justice of the peace, a member of the Craven County–New Bern Committee of Safety , and a field officer of the Craven County  minutemen with the rank of colonel. For some time he acted as treasurer  and accounted for the commissary of prisoners. In 1783 he was named judge of the Admiralty Court, but he resigned that post on 25 Aug. 1787. During a part of the latter period, he was one of two custodians of the Palace Square in New Bern. In 1788 and 1789 he represented Craven County at the conventions held in Hillsborough  and Fayetteville , respectively, to act on the new federal constitution. At the establishment of The University of North Carolina , Leech was an early and generous donor.
As a member of Christ Church, the Anglican parish in New Bern, Leech was an active churchman, and he was a delegate to the convention in 1790 that attempted to organize the Episcopal church in the state. He also was an active Mason  and attended a Grand Lodge meeting in Hillsborough. As a Mason and mayor of New Bern, he read an address of welcome when President George Washington visited the town in April 1791. After attending a banquet and ball in his honor at Tryon Palace , Washington is said to have gone to a smaller party at Leech's home.
Leech's wife was the former Mary Jones, daughter of Frederick and Mary Vail Jones. After her death he married Mary Dorothy Mosley Vail, first cousin of his first wife. In 1788 Leech's daughter, Mary (Polly) Jones Leech, married Richard Dobbs Spaight , governor of North Carolina from 1792 to 1795. According to tradition, Polly Spaight led the first minuet with President Washington at the 1791 ball at Tryon Palace, and in 1795, as the wife of the governor, she was the first woman to attend a commencement program at The University of North Carolina.
Leech and a number of his relatives were buried in the Spaight burial plot across the Trent River from New Bern.
Alexander B. Andrews, Richard Dobbs Spaight (1924).
Kemp P. Battle, History of the University of North Carolina, vol. 1 (1897).
Gertrude S. Carraway, Crown of Life (1940) and Years of Light (1944).
John L. Cheney, Jr., ed., North Carolina Government, 1585–1979 (1981).
Craven County Records (Craven County Courthouse, New Bern).
Halifax North Carolina Journal, 20 June 1796.
Archibald Henderson, Washington's Southern Tour, 1791 (1923).
William L. Saunders, ed., Colonial Records of North Carolina, vol. 6 (1888).
"CSR Documents by Leech, Joseph, 1720-1803." Colonial and State Records of North Carolina. Documenting the American South, University of North Carolina at Chapel Hill. http://docsouth.unc.edu/csr/index.html/creators/csr10371 
Andrews, Alexander B. "Richard Dobbs Spaight." North Carolina Historical Review 1, no. 2 (April 1924). 112-113. http://digital.ncdcr.gov/u?/p249901coll22,651025 
"Portrait, Miniature--Mary Jones Leech. Picture., Accession #: P.TP.1969.010.018 ." late 18th century. North Carolina Tryon Palace.
1 January 1991 | Carraway, Gertrude S.