Polk's primary goal was to negotiate a commercial treaty that would allow the United States to trade with the kingdom on the same terms as Britain, France, and Spain, whose imports to the kingdom received lower tariff rates. Three attempts to negotiate such a treaty—the first by Auguste Davezac in 1833, the second by Enos Throop in 1838, and the third by Polk's predecessor, William Boulware, in 1841—had all failed. Hammett had warned Polk that the kingdom was very protective of its Naples tobacco market, leaving Polk concerned that a treaty might not be possible unless he offered a quid pro quo for the tobacco tariff reductions. Buchanan instructed Polk to focus on obtaining any treaty, no matter how minimal, that would put the U.S. on an equal footing with Britain, France and Spain.