In 1832, U.S. president Andrew Jackson, acting on the advice of Secretary of the Navy Levi Woodbury, dispatched Edmund Roberts as a "special agent of the government," empowered to negotiate treaties of amity and commerce with countries in Asia. The objective was to expand trade between these countries and the United States. Between early 1832 and May 1834, Roberts circumnavigated the globe. In the course of his journey, he negotiated treaties with the Sultan of Muscat (Oman) and the King of Siam (Thailand). Following his return to the United States and ratification of the treaties by the Senate, in 1835 Roberts was sent back to Muscat and Siam to exchange the ratifications. This work, written by the surgeon of the ship that carried Roberts, is an account of the second voyage. In addition to Muscat and Siam, other countries visited on the voyage and described in this work include Brazil, Tanzania, India, Sri Lanka, Indonesia, China, Vietnam, Mexico, Peru, and Chile. Roberts himself did not live to complete his mission. He died in Macao on June 12, 1836.