While he was yet a member of the presidential household, he held that celebrated correspondence with Mr. Jefferson, in which he urged the ex-President to devote the rest of his life to promoting the abolition of slavery. Mr. Jefferson replied that the task was too arduous for a man who had passed his seventieth year. It was like bidding old Priam buckle on the armor of Hector. "This enterprise," he added, "is for the young, for those who can follow it up and bear it through to its consummation. It shall have all my prayers and these are the only weapons of an old man. But, in the mean time, are you right in abandoning this property, and your country with it? I think not." Mr. Jefferson endeavored to dissuade the young man from his project of removal. Mr. Coles, however, was not to be convinced. After serving for six years as private secretary, and fulfilling a special diplomatic mission to Russia, he withdrew to his ancestral home in Virginia, and prepared to lead forth his slaves to the State of Illinois, then recently admitted into the Union, but still a scarcely broken expanse of virgin prairie. He could not lawfully emancipate his slaves in Virginia, and it was far from his purpose to turn them loose in the wilderness. He was going with them, and to stay with them until they were well rooted in the new soil. All his friends and relations opposed his scheme; nor had he even the approval of the slaves themselves, for they knew nothing whatever of his intention. He had been a good master, and they followed him with blind faith, supposing that he was merely going to remove, as they had seen other planters remove, from an exhausted soil to virgin lands. Placing his slaves in the charge of one of their number, a mulatto man who had already made the journey to Illinois with his master, he started them in wagons on their long journey in April, 1819, over the Alleghany Mountains to a point on the Monongahela River. There he bought two large flat-bottomed boats, upon which he embarked his whole company, with their horses, wagons, baggage, and implements. His pilot proving a drunkard, he was obliged to take the command himself, upon reaching Pittsburg.