Marlborough's full transition to a seat of tobacco-planting empire is now clearly discernible. In so becoming, it was typical of the consolidation of wealth, property, and power in Virginia as the mid-century approached. Land had become both a substitute for tobacco in lean years and the means for paying off debts. The same land in better years yielded crops to its new owners, so that a relatively few dynamic men were able to amass great wealth and form a ruling aristocracy. The varieties of talents in men like Mercer--who, besides being a planter, was an accomplished lawyer and able administrator--placed them in the ascendancy over their less able fellows. The vigor and ability with which such men were endowed fostered the remarkable class of leaders of the succeeding generation, who had so much to do with founding the nation.
_Marlborough at its Ascendancy, 1741-1750_
On April 12, 1741, Mercer was admitted to practice at the General Court in Williamsburg.[73] His trip there on that occasion was typical of the journeys which took him at least twice yearly to the capital. On the first day of this Williamsburg trip he rode "To Col^o Taliaferro's," a distance of 19 miles. The following day "To Caroline Court" (18 miles), the next "To M^r Hubbard's" (30 miles), then as far as "M^r J^{ no} Powers" (24 miles), and finally "To Furneas & Williamsburg" (30 miles). The route was usually to West Point, or Brick House on the opposite shore in New Kent County, and thence either directly to Williamsburg, or by way of New Kent courthouse. Stopovers were made either at ordinaries or at the houses of friends.[74]
Mercer's travels, summarized in the journal that he kept in the back of Ledger B from 1730 until his death in 1768, were prodigious. In 1735, for example, he journeyed a total of 4202 miles and was home only 119 days. This pace had slackened considerably in the period we are now considering, but, nevertheless, he was not at home more than 218 days out of any one year of the decade 1741-1750. This energetic and restless moving about was common among the leading planters, but in Mercer's case it seems to have reached its ultimate. Practicing law, playing politics, acquiring property, and becoming acquainted with people led him all over Virginia.