The convention at Williamsburg which began August 1, 1774 lasted for six days and representatives attended from fifty-six counties and four boroughs. Each county sent two delegates and each borough, one. Peyton Randolph was chosen as president of the convention. The convention members agreed to purchase no goods, with the exception of medicine, from Great Britain after November 1, 1774 and agreed neither to import slaves nor to buy imported slaves after November 1. Seven members were selected to represent Virginia at a Continental or General Congress: Richard Bland, Benjamin Harrison, Patrick Henry, Richard Henry Lee, Edmund Pendleton, Peyton Randolph and George Washington. The convention delegates also stated that unless American grievances were diminished by August 10, 1775, all exports of Virginia products to Great Britain would be stopped. It was at this convention that a written treatise on American rights was prepared for the convention by Thomas Jefferson. This paper, later entitled "A Summary View of the Rights of British America," was published by the Virginia convention and was responsible for making Jefferson's great ability as a writer well known. This pamphlet was a forerunner of the Declaration of Independence. While the colonists were having political and economic difficulties with Great Britain, other domestic difficulties were occurring on the frontiers. As mentioned previously, the Piedmont area of Virginia, located between the Fall Line and the Appalachian Mountains, was actually the first American frontier. People who settled there came originally for several purposes: to acquire fertile but cheap land, to enjoy new personal freedom (in many cases, the settlers were former indentured servants), to carry on fur trade with the Indians, to obtain fresh pasture land for cattle and to establish plantations. After the Piedmont area became heavily settled, the westward movement continued. The settlements in the Shenandoah Valley of Virginia followed directly after the crossing of the Blue Ridge Mountains. In the late 1760's, William Bean, a Virginian, constructed the first cabin along the Watauga River, and later, James Robertson and John Sevier pioneered in the Watauga Valley. Settlements were also made at this time along the fertile Holston River Valley in eastern Tennessee. During this period, Daniel Boone explored the Cumberland Gap area and started a settlement in the region now known as Kentucky. While he was taking a group of approximately eighty settlers to this region, he was attacked by a band of Indians. The group decided to return to North Carolina with the exception of the Boone family, and they stopped near the Kentucky-Tennessee border.