Considering all these circumstances, it is somewhat difficult to determine just what was the attitude of the early Virginians toward the slave-trade. There is evidence, however, to show that although they desired the slave-trade, the rate at which the Negroes were brought in soon alarmed them. In 1710 a duty of L5 was laid on Negroes, but Governor Spotswood "soon perceived that the laying so high a Duty on Negros was intended to discourage the importation," and vetoed the measure.[25] No further restrictive legislation was attempted for some years, but whether on account of the attitude of the governor or the desire of the inhabitants, is not clear. With 1723 begins a series of acts extending down to the Revolution, which, so far as their contents can be ascertained, seem to have been designed effectually to check the slave-trade. Some of these acts, like those of 1723 and 1727, were almost immediately disallowed.[26] The Act of 1732 laid a duty of 5%, which was continued until 1769,[27] and all other duties were in addition to this; so that by such cumulative duties the rate on slaves reached 25% in 1755,[28] and 35% at the time of Braddock's expedition.[29] These acts were found "very burthensome," "introductive of many frauds," and "very inconvenient,"[30] and were so far repealed that by 1761 the duty was only 15%. As now the Burgesses became more powerful, two or more bills proposing restrictive duties were passed, but disallowed.[31] By 1772 the anti-slave-trade feeling had become considerably developed, and the Burgesses petitioned the king, declaring that "The importation of slaves into the colonies from the coast of Africa hath long been considered as a trade of great inhumanity, and under its present encouragement, we have too much reason to fear _will endanger the very existence_ of your Majesty's American dominions.... Deeply impressed with these sentiments, we most humbly beseech your Majesty to remove _all those restraints_ on your Majesty's governors of this colony, _which inhibit their assenting to such laws as might check so very pernicious a commerce_."[32] Nothing further appears to have been done before the war. When, in 1776, the delegates adopted a Frame of Government, it was charged in this document that the king had perverted his high office into a "detestable and insupportable tyranny, by ... prompting our negroes to rise in arms among us, those very negroes whom, by an inhuman use of his negative, he hath refused us permission to exclude by law."[33] Two years later, in 1778, an "Act to prevent the further importation of Slaves" stopped definitively the legal slave-trade to Virginia.[34]