The Onslow County Courthouse is located at 625 Court Street, Jacksonville, NC 28540; phone: 910-455-4458.
Onslow County's initial European settles were probably attracted by the abundant forest and marine resources of the area. Little is known about these early settlers, but presumably had come to the area for warrant the formation of the county from New Hanover County in 1734.
In 1754 the county had a population of 695 taxable inhabitants of whom 448 were adult white male taxables and 147 were male and female black slaves. In 1767 the number of taxable inhabitants was 1,216, including 500 black slaves. These statistics suggest the early importance of slavery in the county, probably as a component of nascent tar and turpentine plantations, for in 1820, 40 percent of Onslow County's slave population of 3,604 worked in "manufacturing" (turpentine production). This percentage was well above the national average of 5 percent of slaves engaged in manufacturing operations.
The ethnic composition of the county's other early citizens was apparently mixed. Probably a majority came from adjacent settlements on the North Carolina seaboard, from the Lower Cape Fear, and from the environs of New Bern. Others probably arrived more or less directly from Western Europe, from New England, and from the West Indies, as suggested by county and genealogical records and census returns. Several leading farmers and terpentiners of the late 19th century resettled after the Civil War. By the early 19th century, the Brock, Franck, and Huffman families had settled in the section of the county southeast of Richlands, an area referred to in Canin's 19th century New Germany.
The nature of Onslow County's resources and its proximity to the ocean connected it to an extensive network of Atlantic trade. The resource-poor West Indies were an early market for Onslow naval stores and lumber. Onslow County merchants and turpentine planters maintained trade contacts in major Eastern Seaboard centers such as Baltimore and New York. These varied ethnic and trade relationships probably helped to mold the county's culture.