Moreover, Dunmore was interested in great land speculations on his own account; and while overtly vindicating Virginia's claim to the trans-Alleghany by despatching parties of surveyors to the western wilderness to locate and survey lands covered by military grants, he with the collusion of certain members of the "Honourable Board," his council, as charged by Washington, was more than "lukewarm," secretly restricting as rigorously as he dared the extent and number of the soldiers' allotments.

According to the famous Virginia Remonstrance, he was in league with "men of great influence in some of the neighboring states" to secure, under cover of purchases from the Indians, large tracts of country between the Ohio and the Mississippi." In shaping his plans Dunmore had the shrewd legal counsel of Patrick Henry, who was equally intent upon making for himself a private purchase from the Cherokees.

It was Henry's legal opinion that the Indiana purchase from the Six Nations by the Pennsylvania traders at Fort Stanwix (November 5, 1768) was valid; and that purchase by private individuals from the Indians gave full and ample title.

In consequence of these facts, William Murray, in behalf of himself and his associates of the Illinois Land Company, and on the strength of the Camden Yorke decision, purchased two large tracts, on the Illinois and Ohio respectively, from the Illinois Indians (July 5, 1773); and in order to win the support of Dunmore, who was ambitious to make a fortune in land speculation, organized a second company, the Wabash (Ouabache) Land Company, with the governor as the chief share-holder.

In response to Murray's petition on behalf of the Illinois Land Company, Dunmore (May, 1774) recommended it to Lord Dartmouth, Secretary of State for the Colonies, and urged that it be granted; and in a later letter he disingenuously disclaimed any personal interest in the Illinois speculation.
The party of surveyors sent out under the direction of Colonel William Preston, on the request of Washington and other leading eastern men, in 1774 located lands covered by military grants on the Ohio and in the Kentucky area for prominent Virginians, including Washington, Patrick Henry, William Byrd, William Preston, Arthur Campbell, William Fleming, and Andrew Lewis, among others, and also a large tract for Dr.Connolly.Certain of these grants fell within the Vandalia area; and in his reply (September 10, 1774) to Dunmore's letter, Lord Dartmouth sternly censured Dunmore for allowing these grants, and accused the white settlers of having brought on, by such unwarrantable aggressions, the war then raging with the Indians.