Born in Ireland in 1729, William Preston came to America when he was eight. By eighteen, the death of his father prompted Preston to leave his studies and join his uncle as a surveyor. He fought during the French and Indian War where he was made Ranger Captain.
In 1760 at the age of thirty-one, Preston married Susannah Smith and went west to live near Fincastle. There they purchased a house called Greenfield. By 1774, Preston moved his wife and their six children into a new house in Montgomery County. Smithfield received its name in honor of Preston's wife Susannah (Smith).
It was wild country and Indian attacks were always possible. By 1777, the added tensions of the Revolutionary War could be felt on the frontier. The area had many German immigrants that had no quarrel with the King in England, who was of German descent. Preston did not listen to advice to move his family, but instead helped raise troops and plan the campaign of King's Mountain. Both Tories and Indians plagued him throughout the revolution.
After the surrender at Yorktown, life at Smithfield returned to normal. However, the stress of the conflict and the loss of his younger daughter Nancy had taken its toll on the colonel. He died in 1783 leaving his wife to run the plantation for forty more years. Collections of letters in the Library of Congress and other major libraries chronicle the challenges for Susannah Preston and later, her children, in running the plantation.