Another expansion at this time also on the south side of James River was the formation of Sussex from Surry County. Sussex lies to the south of Seacock Swamp on the line dividing Surry "from the county of Southampton, thence a straight course to Blackwater at the mouth of Coppohawk and up Blackwater to the line dividing" Surry from the county of Prince George. Sussex took its name from the English shire. Albemarle Parish formed in 1739 had included the area now made into Sussex, and, in addition, a small portion of Surry. It was enacted that the portion in Surry be added to Southwark Parish, and Albemarle Parish be made coterminous with Sussex.
The fourth county formed in 1754 was Hampshire named for the English shire. It is now in West Virginia. Since, however, its creation affected the bounds of two already established Virginia Counties, the Act of Assembly for its bounds is cited: "Whereas part of the county and parish of Augusta lies within the bounds of the territory or tract of land called the Northern Neck belong to the right honorable Thomas, Lord Fairfax, Baron of Cameron and it will be more convenient if the dividing line between the said territory and the other part of this colony be established as the line of the said county and that part of the said county be added to the county and parish of Frederick," it was enacted therefore that the part of Augusta above mentioned be added to Frederick which should then be divided into two counties and "all that part thereof lying to the westward of the ridge of mountains commonly called and known by the name of the Great North or Cape Capon mountains and Warin spring mountain extending to Potomac river be one distinct county and called and known by the name of Hampshire." When Augusta and Frederick were authorized in 1738, the western bounds of the Northern Neck Grant had not been surveyed. This was done in 1747, and the above Act changed the previous limits of Augusta so that the entire county would not be a part of the proprietary.
The name of the next new county reflected current happenings. For about six years, 1754-1760, the colony was actively participating in the struggle to crush French power in America. The Commander-in-Chief of the British Forces in America was, for a time, John Campbell, fourth Earl of Loudoun. His conduct of the war was severely criticized, and he was recalled in December 1757. He was, for almost two years, titular "Governor and Captain-General of Virginia," though his deputy Lieutenant-Governor Robert Dinwiddie performed all the duties of the office. Loudoun, the new county named for the Earl, was formed from Fairfax County in 1757. It included "all that part thereof lying above Difficult Run which falls into Potomac river and by a line to be run from the head of the said run or straight course to the mouth of Rocky run." The part "thereof below the said run and course" retained its status as a distinct county and the name of Fairfax.