In addition to the improvement of the plant, Rolfe was one of the first regularly to grow tobacco for export and as such was the father of the Virginia tobacco trade and industry. The first experimental shipment of the newly developed Virginia leaf came about 1613, and because of its pleasant taste it was well received in some quarters. Production was slow for several years. Dale restricted its cultivation until basic commodities, such as corn, were well advanced. In the 1615-16 period only 2,300 pounds reached London from Virginia. Capt. George Yeardley, the next to govern, gave the new crop his whole-hearted support, with the result that in 1617 exports reached the 20,000 pound total, and by 1619 this had been more than doubled. Thus, a new trade and industry were born in the colony, which proved to be the economic salvation of Virginia, and provided a means for making slavery profitable. Tobacco and slavery together led to the development of important characteristics of the whole social, political, and economic structure of the Old South. One of the immediate effects of tobacco culture in Virginia was the impetus it gave to the expansion of the area of settlement and to the number of settlers coming to Virginia. [Illustration: _Tobacco cultivation as practiced at Jamestown. (A conjectural painting by Sidney E. King.)_] THE SPREAD OF SETTLEMENT. Jamestown was planned as the first permanent English settlement in Virginia. The fixed intention was to establish other seats as soon as possible. As the limitations of Jamestown became obvious, the desire for other townsites was intensified. Soon after the settlement was made at Jamestown, temporary garrisons were placed at outlying points for protective and administrative reasons—at Kecoughtan (Hampton-Newport News), Cape Henry, and at the falls of the James. The first efforts in this direction, except at Kecoughtan, ended in the autumn of 1609 under pressure from the Indians. With the arrival of Delaware, Kecoughtan (renamed Elizabeth City in 1619) was established as a permanent settlement. Dale and Gates went on to establish the city of Henricus (Henrico) well up the James near the falls. Then came Charles City (the earlier Bermuda Nether Hundred) which developed into the last of the four settlements established by the company, each of which had the designation “city.” These four settlements were the only towns specifically set up by the company and consequently under its complete control. These later came to be mentioned in the records as the “Four Ancient Boroughs” or “four ancient Incorporations.” As one of these, Jamestown became the center of the political subdivision that developed into one of the original Virginia shires in 1634. Within the next decade the term county replaced that of shire, and today, although Jamestown has ceased to exist as a corporate organization, James City County continues to function as the oldest governing unit in English America.