In the Virginia Magazine of History and Biography, Vol. 73, No. 3, I found this information:
Three generations of Leonard Hills lived at Hill Park on the Rappahannock River, about halfway between Ware’s Wharf and Bowler’s Wharf.
(Source cited: Essex Co. Deeds, XLVI, 147; ibib. XXXI, 352)

No mention in here of Leonard Hill (I).

Leonard Hill (II) of Essex Co. m. Mary Micou.
After Leonard (II) died (no date stated), widow Mary Micou Hill married Joshua Fry before 1736. Fry lived at Hill Park and became a vestryman of South Farnham Parish (1738-1742) and a justice of Essex Co. (1736-1742).
(Source cited: Essex Orders, X 31, 260, XIII, 6)

Joshua Fry moved to Albemarle Co. in 1745.
Source cited: W & M Quarterly, ser.2 XVI, 490; Douglas Southall Freeman, George Washington, A Biography, I, 339)

Leonard Hill (III) of Essex Co. married Sarah Thacher, daughter of Col. Edwin Thacher of Middlesex Co., in 1752.
Leonard Hill (III) died in 1756 and left two daughters:
- Elizabeth Hill, m. James Dunlop of Port Royal in Caroline Co. in 1774;
- Mary Hill, m. Bennett Browne of Middlesex Co. in 1775.
(Sources cited: W & M Quarterly, ser 2 XVI, 49)
After Leonard (III) died, Sarah m. James Campbell, warden and vestryman of South Farnham Parish, Essex Co. He died in 1774.
(Source cited: Essex Deeds, XXI, 201)
Widow Sarah Thacher Hill Campbell died before 1798.
(Source cited: Essex Co. Wills, XIII, 467)

In the book, The Diary of Robert Rose: A View of Virginia by a Scottish Colonial Parson, 1746-1751, I this information on page 227, annotation #427:
“John Lee of Smithfield near present Champlain and clerk of Essex County married Mary Hill, daughter of Leonard Hill and Mary (Micou) Hill whose second husband was Joshua Fry. The marriage occurred at Port Micou, home of John Micou , older brother of Mary (Micou) Hill Fry.
Two sisters of Mary (Hill) Lee were Elizabeth Hill who married James Dunlop, merchant of Port Royal, where her grave marker is dated 1780; and Anne Hill who married Richard Tunstall of King and Queen County.”
On page 344 is listed the marriage by Parson Robert Rose of John Lee and Mary Hill, Essex County on September 3, 1748.

Does anyone have additional information about these Leonard Hills?