Fry was born in Crewkerne, Somerset, England, the son of Joseph Fry, in or about 1700. He attended Wadham College, Oxford University, and moved to Virginia about 1726. Fry secured a teaching position at the College of William and Mary, where he served as the master of the grammar school in 1729, and then, by 1732, as the professor of natural philosophy and mathematics. He also served James City County as a justice of the peace. In the mid-1730s Fry resigned his teaching position (some scholars place this event in 1737) and moved to Essex County, where he served as a justice of the peace, sheriff, and coroner. There, he married Mary Micou Hill, a widow through whom Fry acquired a house, land, and several slaves. Fry and his wife had five children.
In 1738 Fry, Robert Brooke, and William Mayo presented to the House of Burgesses a plan to survey and create an official map of the Virginia colony. They made their proposal late in the session, and the House postponed deliberation from session to session until September 1744, when, finally, it rejected the plan. By this time, Fry was living along the Hardware River in Goochland County. When Albemarle County was formed from Goochland in 1745, his property was located in the newly formed county. He was commissioned to survey the Albemarle–Goochland county boundary line. Fry also served as a justice in the Albemarle County and Chancery Courts, was appointed first lieutenant of the county, and was elected to represent Albemarle County in the House of Burgesses, serving on several of its committees from 1745 until his death in 1754.
It was in Albemarle County that Fry likely met Peter Jefferson, his collaborator on the Fry-Jefferson map. Fry and Jefferson first worked together in 1746, when Lieutenant Governorappointed them to establish the Fairfax Line, the western boundary of the lands belonging to Thomas Fairfax, sixth baron Fairfax. In 1749, they collaborated again to determine the Virginia–North Carolina dividing line, which was to be extended ninety miles, to Steep Rock Creek on the east of Stone Mountain, to accommodate the continued westward movement of land speculators and settlers into the rugged . Fry and Jefferson represented Virginia and worked with their North Carolina counterparts to survey the boundary line’s extension.
In 1750, the British were concerned about the evident failure of the Treaty of Utrecht, signed by the British and the French to resolve Queen Anne’s War (1702–1713). The treaty had determined the boundaries of French and British claims to lands in North America, but was not specific enough to prevent territorial disputes between the two countries. As a result, the British and French had different interpretations of their mutual boundary. The Ohio Company and the Loyal Land Company, of which Joshua Fry was a member, owned huge tracts of land in areas west of the Allegheny Mountains, and many of these holdings encroached on territory the French claimed as theirs. After George Montague Dunk, earl of Halifax and president of the, asked the British colonies in 1750 for more information about activities on the frontier, , acting governor of Virginia, commissioned Fry and Jefferson to prepare a map of the colony.
In compiling the map, Fry and Jefferson relied on their own surveys and experiences to supplement existing published maps, manuscript maps, and field notes. Fry also composed a report on the Virginia backcountry called “An Account of the Bounds of the Colony of Virginia of its back Settlements of the lands toward the Mountains and Lakes.” The report relies on four published sources, with Fry’s own comments interspersed. Fry also included a handwritten copy of “A Brief Account of the Travels of John Peter Salley,” which documents John Howard’s 1742 expedition along the Ohio and Mississippi rivers. In 1751 Fry and Jefferson delivered their draft to Burwell, who then forwarded it to the Board of Trade. A Map of the Inhabited Part of Virginia containing the whole Province of Maryland, with Part of Pensilvania, New Jersey and North Carolina was officially presented to the commissioners in March 1752.
Fry’s reputation and knowledge of the Virginia frontier led Lieutenant Governor Robert Dinwiddie to appoint Fry as one of the commissioners for the Treaty of Logstown (1752). The treaty served multiple purposes, one of which was to strengthen the relationship between the English colonists and the American Indians. Representatives of the Six Nations of the Iroquois promised to recognize English land claims southeast of the Ohio River; however, the terms of the treaty were contingent upon the approval of the Iroquois council fire at Onondaga.
In 1754, at the beginning of the French and Indian War (1754–1763), Dinwiddie commissioned Fry colonel and head of the Virginia Regiment. Headed for the Ohio River Valley, Fry marched his troops to Wills Creek in present-day Cumberland, Maryland. During the journey he fell from his horse and suffered severe injuries. He died on May 31, 1754, and was replaced as head of the Virginia Regiment by his second-in-command,.