Although Mercer apparently found surcease from his cares in the peaceful surroundings at Marlborough, his responsibilities went on nevertheless. The cost of keeping slaves remained an enormous and wasteful one: "Every negroes cloaths, bedding, corn, tools, levies & taxes will stand yearly at least in £5," he wrote to George. In his letter he placed an order through George for clothing, which included 25 welted jackets "for my tradesmen & white servants," indicating the large number of white workmen on his staff. It also included 20 common jackets, 45 pair of woolen breeches, 1 dozen greatcoats, 5 dozen stockings, 1-1/2 dozen for boys and girls, 4 dozen "strong felt hats & 600 Ells of ozenbrigs. We shall make Virg^a cloth enough to cloath the women and children, but shall want 50 warm blankets & 2 doz of the Russia drab breeches." Against the advice of his merchant friend Jordan, he declined to order a superior grade of jacket for his Negroes that would last two years, since "most negroes are so careless of their cloathes & rely so much on a yearly support that I think such jackets as I had are cheapest & last the year very well."
He ordered George to buy new sheeting for family use, including "84 yds of such as is fit for comp^a," inasmuch as "my wife is ashamed of her old sheets when any strangers come to the house." He also placed an order for windmill sails, which, he observed, were costly in the colony, and could be made only at Norfolk.
My millwrights directions were The Drivers 3 foot 6 inches broad } } 23 feet long. The leaders 3 3 }
A Suit I had made at Norfolk by those dimensions proved too long, something, they should be of Duck N^o. 2.
In addition, he ordered nails, 50 yards of haircloth, a yard wide, for the malt kiln, a "drill plow with brass seed boxes for wheat, turnips, lucarn pease &c," and a considerable number of books, particularly for his children. "Bob. Newbery at the Bible & Sun in S^t. Paul's churchyard can best furnish you at the cheapest rate with books best adapted to the real instruction as well as amusement of children from two to six feet high."
The long letter was finally finished on January 28, 1768, its great length partly dictated by the fact that the river had frozen, immobilizing the posts. He noted in his journal that on February 16 he was in Fredericksburg and "dined at my Sons being my birthday and 63 y^{ rs} old." On the 24th he attended a meeting of the Ohio Company at Stafford courthouse and on March 14 returned there for a court session. The next day he went home to Marlborough, perhaps never to leave again. The journal ended at the close of the month. The next that we hear of him appeared in Rind's _Virginia Gazette_ on October 27: