Colonel Thomas Marshall was born on 30 April 1730 in Westmoreland County, Virginia, to Captain John Marshall and his wife, Elizabeth Markham. A childhood friend and neighbor was George Washington, and the two would become close friends for the remainder of their lives.

George Washington became a surveyor for Lord Fairfax, the proprietor of the Northern Neck of Virginia, a royal grant in excess of five million acres, which occupied a quarter of the colony at that time. Fairfax wanted to survey his land and encourage settlers to live there. Washington obtained employment with Lord Fairfax for his boyhood friend, Thomas Marshall, who had also become a surveyor. When Thomas Marshall's father died in 1752, he had moved to the area known as Germantown in present day Fauquier County.

Thomas became a member of the first court of Fauquier County and represented the county in the House of Burgesses in the 1760's and 70's. By 1773, Colonel Marshall had accumulated more wealth. He purchased an estate near the north Cobbler Mountain, paying almost one thousand 

         Mont Blanc

- The Hollow - John Marshall's boyhood home

In 1754, Thomas Marshall married Mary Randolph Keith, the daughter of the Reverend James Keith of Hamilton Parish. The two lived in a small home in Germantown and began their family which would grow to fifteen children. Thomas collected quitrents for Lord Fairfax, and later served as tax collector and as sheriff.

After the birth of their third child, they moved to a lease on a Lee grant near present-day Markham and built a small house known as "The Hollow", near the banks of Goose Creek, in the early 1760's. The house, which still stands, measured 16 x 2O feet - had two rooms on the first floor and two rooms in the loft. Here, the next seven children were born. It is hard to imagine the parents and ten children living in four small rooms. It must have been a lively household!