Henderson soon acquired a good practice and became a judge on the bench of the Superior Court. In 1774 the conflict with the British agent in North Carolina was precipitated, and the colonial government was abolished. It was at this time that Judge Henderson became interested in the desire of the Cherokee Indians to sell land. Henderson's plan was to purchase from the Cherokees the great territory lying south of the Kentucky River--one-half the present state of Kentucky. This was quite against the laws and traditions of the only colony which had any valid claim to the territory--Virginia, his native state--but this seemed to matter not to Henderson and his associates; these were John Williams, under whom Henderson had studied law, Leonard Henley Bullock, James Hogg, Nathaniel Thomas, David Hart, John Luttrell, and William Johnstone. At the very beginning of the century Virginia had passed an act forbidding the private purchase of lands from the Indians. The founders of Transylvania evidently doubted Virginia's sweeping claims to the entire interior of the continent--at any rate land companies seemed to be the only means by which the vast wildernesses beyond the mountains could be opened up and settled. Though Virginia soon proved the invalidity of the purchase, she at the same time was frank enough to admit that Henderson's Company had done a good work in giving an impetus to westward expansion, by appropriately recompensing the North Carolinians for their expenditure and labors. Henderson's purchase was gigantic in its proportions, embracing nearly twenty million acres. The consideration was ten thousand pounds sterling. The purchase was made at the advance settlement at Watauga, March 17, 1775--only a month before the outbreak at Lexington and Concord. Henderson employed Boone to assist in the transaction, and immediately after engaged him to mark out the road through Cumberland Gap to a settlement in Kentucky, where the Transylvania Company (as Henderson strangely named his organization) was to begin the occupation of the empire it had nominally secured. Of this Boone writes modestly that he was "solicited by a number of North Carolina gentlemen, that were about purchasing the lands lying on the south side of the Kentucky River, from the Cherokee Indians, to attend their treaty at Watauga, in March, 1775, to negotiate with them, and mention the boundaries of the purchase. This I accepted, and at the request of the same gentlemen undertook to mark out a road in the best passage from the settlement through the wilderness to Kentucky, with such assistance as I thought necessary to employ for such an important undertaking."