sentences:  Poinsett was initially sent to negotiate the acquisition of new territories for the United States, including Texas, New Mexico, and Upper California, as well as parts of Lower California, Sonora, Coahuila, and Nuevo León; but Poinsett's offer to purchase these areas was rejected by the Mexican Ministry of Foreign Affairs headed by Juan Francisco de Azcárate.He became embroiled in the country's political turmoil until his recall in 1830, but he did try to further U.S. interests in Mexico by seeking preferential treatment of U.S. goods over those of Britain, attempting to shift the U.S.–Mexico boundary, and urging the adoption of a constitution patterned on that of the U.S. Poinsett often interfered in the Affairs of the newly born Republic, and provoked disagreements with British charge d'affaires Henry George Ward.Texas remained a focal point of U.S-Mexico relations for decades.