Maps are such a great source of history, and this 1766 map doesn’t disappoint those looking to learn more about Somerset County, New Jersey’s history. Completed in 1766 by surveyors Benjamin Morgan and Joseph Hills, the Morgan–Hills Map is the earliest known comprehensive landownership map of Somerset County, New Jersey.
Created just ten years before the American Revolution, it records more than 165,000 acres, identifying individual landowners, property boundaries, roads, rivers, churches, mills, and early settlements. More than a map, it provides a remarkable snapshot of colonial Somerset County, revealing how a handful of wealthy proprietors shaped the farms, villages, and communities that would define the county for generations to come.
Among the more than 150 landowners identified on the map, five landholding interests stand above the rest. Peter Sonmans, John Harrison, William Penn, James Alexander & Charles Dunster, and Campbell & Blackwood together controlled approximately 87,544 acres, more than 52.88% of all the land in Somerset County. Their enormous proprietary estates shaped where roads, farms, villages, churches, and mills would develop, leaving a lasting imprint on the county’s landscape that is still evident today.
5. Campbell & Blackwood
Northern Bedminster and Peapack Valley
By 1766, the partnership of Campbell & Blackwood ranked as the fifth-largest landholding interest on the Morgan–Hills Map of Somerset County, controlling approximately 6,420 acres, or 3.88% of the county’s total acreage. Their holdings were concentrated primarily in present-day Bedminster Township, including portions of the Peapack Valley and neighboring lands that would later become Peapack-Gladstone. Like several of the county’s largest proprietors, Campbell and Blackwood were land investors rather than resident farmers, assembling large tracts with the expectation that settlement would steadily increase the value of their holdings.
John Campbell and Robert Blackwood were among the influential East Jersey Proprietors and merchants who invested heavily in New Jersey’s frontier lands during the early eighteenth century. Through proprietary grants and strategic purchases, they acquired extensive acreage in Somerset County, becoming part of a network of wealthy investors who shaped the county’s early settlement. Their interests reflected the colonial practice of purchasing large wilderness tracts, surveying them into smaller parcels, and gradually selling or leasing them to incoming settlers.
Although relatively little is known about the families of Campbell and Blackwood compared with landowners such as James Alexander or William Penn, their properties remained active long after their deaths through heirs, trustees, and representatives. As a result, the partnership name continued to appear on maps and deeds for decades, including the 1766 Morgan–Hills Map, even as individual farms were being transferred to new owners.
Over the second half of the eighteenth century, the Campbell & Blackwood properties were gradually subdivided into productive farms that helped shape the agricultural landscape of northern Bedminster and the Peapack Valley. Many of the local families whose names appear elsewhere on the 1766 Morgan–Hills Map eventually acquired portions of these former proprietary lands, transforming one of Somerset County’s largest speculative investments into the farms, roads, and communities that would define the region during the Revolutionary War era.
4. James Alexander & Charles Dunster
Bernards, Bedminster, and parts of Bridgewater
By 1766, the land partnership of James Alexander and Charles Dunster ranked as the fourth-largest landholding interest in Somerset County, controlling approximately 6,724 acres, or 4.06% of all the land shown on the Morgan–Hills Map. Their investments were concentrated primarily in present-day Bernards, Bedminster, and parts of Bridgewater, where they acquired large proprietary tracts decades earlier as long-term land speculators rather than resident farmers. Although both men had died before the map was published, their names remained attached to many parcels because ownership records had not yet been updated, preserving the legacy of one of colonial New Jersey’s most significant land partnerships.
James Alexander (1691–1756) was one of the most influential men in colonial New Jersey. Born in Scotland, he fled to America after supporting the unsuccessful Jacobite uprising of 1715 and quickly established himself as a surveyor, attorney, and political leader. Appointed Surveyor General of both New Jersey and New York, he became Attorney General of New Jersey in 1723 and gained lasting fame as one of the principal defenders of printer John Peter Zenger in the landmark 1735 freedom of the press trial. Beyond his legal career, Alexander amassed an enormous fortune through land speculation, acquiring tens of thousands of acres across northern New Jersey, including extensive holdings throughout Somerset County. Many of those tracts still appeared in his name on the 1766 Morgan–Hills Map, even though he had died a decade earlier, illustrating both the size of his estate and the slow transfer of colonial land titles.
James Alexander married Mary Spratt Provoost, the widow of wealthy merchant David Provoost, and together they raised several children who became members of some of colonial America’s most prominent families. Their only son, William Alexander (1726–1783), inherited much of his father’s New Jersey property and later became famous as Lord Stirling, one of General George Washington’s most trusted major generals during the American Revolution. Their daughters married into the Livingston, Stevens, Reid, and Rutherfurd families, extending the Alexander family’s influence throughout New York and New Jersey politics for generations. Through William’s ownership of the Stirling estate near Basking Ridge, James Alexander’s legacy became permanently connected to Somerset County and the Revolutionary War.
Charles Dunster, who died in 1727, was a wealthy Perth Amboy merchant, East Jersey Proprietor, and one of colonial New Jersey’s largest land investors. Rather than settling the wilderness himself, Dunster purchased vast proprietary tracts as long-term investments, acquiring thousands of acres throughout the Raritan Valley and what would later become Somerset County. Surviving land deeds show him actively buying and selling large parcels along the North Branch of the Raritan River during the 1720s, making him one of the colony’s most significant absentee landowners. After his death, his estate remained tied up in legal proceedings for many years, and ownership of many of his lands continued under the Dunster name long after he was gone.
The connection between James Alexander and Charles Dunster explains why the name “Alexander & Dunster” appears so prominently on the 1766 Morgan–Hills Map. The two men worked together to acquire and manage large proprietary landholdings, combining their financial resources to purchase enormous tracts that they later leased or sold to settlers. Numerous Somerset County deeds from the eighteenth century record land being conveyed by “James Alexander and Daniel Donaldson Dunster,” acting as representatives of the Dunster interests, demonstrating that the partnership continued even after Charles Dunster’s death, with Alexander helping to administer and dispose of portions of the properties. By 1766, many farms were occupied by local families, yet the original proprietary ownership was still reflected on the map, preserving the names of the investors who had assembled these vast colonial estates decades earlier
Unlike many of the families shown on the 1766 map, James Alexander and Charles Dunster left relatively few surviving structures. James Alexander’s greatest physical legacy is the site of Lord Stirling Manor in Basking Ridge, where archaeological remains and original eighteenth-century outbuildings preserve the estate that his son, William Alexander (Lord Stirling), inherited.
Over the following decades, the vast Alexander and Dunster holdings were gradually surveyed, subdivided, and sold to settlers, transforming speculative wilderness into productive farms. Many of the families whose names appear throughout the 1766 Morgan–Hills Map, including the Parkers, Campbells, Boyles, Coxes, Ayres, and others, ultimately acquired portions of these original proprietary lands. In this way, the Alexander and Dunster partnership helped lay the foundation for many of the farms, villages, and communities that would shape Somerset County during the Revolutionary War and beyond.
Charles Dunster’s legacy is represented by the Dunster House (Dunster–Squibb House) in Bernardsville, built by his grandson, Revolutionary War veteran James Dunster, around 1805 and now undergoing preservation. Together, these sites serve as lasting reminders of two of the largest landholding families in colonial Somerset County.
3. William Penn
Western Bedminster Township
By 1766, the properties of William Penn ranked as the third-largest landholding interest on the Morgan–Hills Map of Somerset County, controlling approximately 13,000 acres, or 7.85% of the county’s total acreage. Penn’s holdings were concentrated primarily in the western portion of present-day Bedminster Township, where large proprietary tracts had been surveyed and reserved decades earlier. Although William Penn had died in 1718, his name remained on these lands because many parcels were still held by his heirs or under the original proprietary title, reflecting the enduring influence of one of colonial America’s most prominent landowners.
William Penn (1644–1718) was an English Quaker, religious reformer, and founder of the Province of Pennsylvania. In addition to establishing one of the most successful colonies in North America, Penn became one of the twenty-four Proprietors of West Jersey and acquired substantial land interests in neighboring East Jersey through investment and proprietary agreements. His vision of orderly settlement, religious tolerance, and carefully planned land distribution made him one of the most influential colonial figures of the seventeenth and early eighteenth centuries. While he never resided in Somerset County, his extensive landholdings helped shape its early settlement and development.
William Penn married twice. His first wife, Gulielma Maria Springett, died in 1694, and in 1696 he married Hannah Callowhill, who became an able administrator of the Penn properties after his death. Their sons, particularly John, Thomas, and Richard Penn, inherited and managed the family’s vast proprietary interests in both Pennsylvania and New Jersey. Through their stewardship, the Penn family remained among the largest landowners in the region for generations, and the William Penn name continued to appear on maps and deeds long after his death.
Unlike James Alexander and Charles Dunster, William Penn left no surviving residence in Somerset County. His legacy is instead reflected in the orderly pattern of settlement that spread across western Bedminster as his proprietary lands were surveyed, sold, and developed into farms. Many of the families appearing on the 1766 Morgan–Hills Map eventually purchased portions of these former Penn holdings, helping transform a vast proprietary property into the agricultural landscape that characterized Somerset County during the Revolutionary era.
2. John Harrison
Bernards Township & Bridgewater Township
By 1766, John Harrison ranked as the second-largest landholder on the Morgan–Hills Map of Somerset County, controlling approximately 17,800 acres, or 10.75% of the county’s total acreage. His holdings were concentrated primarily in present-day Bridgewater Township, where they bordered and followed the waterway now known as Harrison Brook. The brook, which still bears the family name today, is widely believed to have been named for the Harrisons, providing one of the few surviving geographic reminders of Somerset County’s largest colonial landowner.
John Harrison (c. 1680–1749) was one of colonial New Jersey’s wealthiest merchants, public officials, and landowners. A prominent resident of Perth Amboy, he served on the Governor’s Council and invested heavily in land throughout the colony. Through proprietary grants and strategic land purchases, Harrison assembled one of the largest private estates in colonial New Jersey, making his name a familiar one on eighteenth-century maps and deeds.
On June 24, 1717, John Harrison acquired approximately 3,000 acres from Chief Nowenoik of the Lenni Lenape, a tract that became known as Harrison’s Purchase or Harrison’s Neck and laid the foundation for much of the early settlement of Bernards Township.
John Harrison married Elizabeth Bassett, and their children and descendants inherited and managed much of the family’s extensive landholdings after his death. Although portions were gradually divided and sold, the Harrison name continued to appear on maps and property records for decades, reflecting the lasting influence of one of Somerset County’s most significant colonial landowners.
Over the following decades, the Harrison properties were subdivided into smaller farms that were purchased by local families and new settlers. Those former Harrison lands formed the foundation of many of the farms and communities that shaped Bridgewater Township during the Revolutionary War era, while Harrison Brook continues to preserve the family’s name in the modern landscape.
Harrison Brook flows south through the heart of present-day Bridgewater Township, winding across lands once owned by John Harrison before eventually reaching the Raritan River. More than 250 years later, the brook continues to preserve the name of one of Somerset County’s largest colonial landowners.
1. Peter Sonmans
Montgomery, Hillsborough, Franklin, and Southern Bridgewater
By 1766, Peter Sonmans ranked as the largest landholder on the Morgan–Hills Map of Somerset County, controlling approximately 43,600 acres, or 26.34% of the county’s total acreage. His vast proprietary holdings were concentrated in present-day Montgomery, Hillsborough, Franklin, and the southern portions of Bridgewater, where they encompassed some of the largest uninterrupted tracts in colonial New Jersey. Although Sonmans had died more than thirty years before the map was published, his name remained attached to these immense holdings because they were still held under the original proprietary title, making him the county’s largest recorded landowner.
Peter Sonmans (1677–1734) was born in the Netherlands and educated at the University of Leiden before settling in East Jersey. The son of Arent Sonmans, one of the original Twenty-Four Proprietors of East Jersey, he inherited extensive proprietary interests and became one of colonial New Jersey’s most influential public officials. He served as Surveyor General of East Jersey, was a member of the Governor’s Council, served in the General Assembly, and held numerous judicial appointments. Beyond public service, Sonmans expanded his family’s landholdings into one of the largest private estates in the colony, investing heavily in the fertile lands of what would become Somerset County.
Peter Sonmans married Sarah Nevill, the sister of Judge Samuel Nevill, and they had one son, Dr. Peter Sonmans Jr., a respected Philadelphia physician. Unlike many of the great colonial landholding families, the Sonmans’ Propertyies was not preserved through generations of direct descendants. Following Peter’s death in 1734, his vast proprietary holdings were administered by family members, trustees, and representatives of the properties, with Judge Samuel Nevill playing an important role in managing them. Over the next century, thousands of acres were gradually surveyed, partitioned, and sold, transforming one of New Jersey’s largest proprietary estates into hundreds of individually owned farms.
The gradual sale of the Sonmans’ properties during the late eighteenth and early nineteenth centuries reshaped Somerset County. Large proprietary tracts gave way to family farms, mills, churches, and growing villages as settlers purchased parcels. Much of present-day Montgomery, Hillsborough, Franklin, and southern Bridgewater developed from these former Sonmans lands, and many of the families whose names appear elsewhere on the 1766 Morgan–Hills Map ultimately acquired portions of this enormous estate. Although the Sonmans name gradually disappeared from deeds and maps, the subdivision of his holdings helped establish the agricultural landscape and communities that defined Somerset County for generations.
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