The 1750 Treaty of Madrid prompted Portuguese civil and ecclesiastical authorities under Sebastião José de Carvalho e Melo (later the Marquis of Pombal) to strengthen crown control of the Brazilian Amazon. Pombal's brother, Francisco Xavier de Mendonça Furtado, governor and captain-general of the State of Grão-Pará and Maranhão, and Bishop Fr. Miguel de Bulhões e Sousa sought to supplant the missionaries, especially the Jesuits, and rein in autonomous backwoods Indian traders, called cunhamenas (Tupi for male in-law). The Lisbon Inquisition collaborated by prosecuting the infamous mameluco Pedro de Braga, a powerful interethnic intermediary on the Rio Negro, who was condemned for practicing indigenous rites and accepting multiple wives from tribal chiefs.

Many instructors face challenges in engaging students in lecture courses. In the fall of 2004, we incorporated innovative, real-time polling technology into an upper-division political science course on Public Opinion. The polling technology channeled students' technological savvy in the service of several pedagogical goals. The technology increased student engagement and reinforced the substance of the course material. It also provided students with topically relevant experiences in answering survey questions and allowed students to feel more comfortable in expressing their opinions during discussions.We thank Victoria Cross, James Fowler, Ethan Scheiner, Walter Stone, and Elizabeth Zechmeister for helpful suggestions. Funding for the technology was generously provided by the Undergraduate Instructional Improvement Program, supported by the vice provost–undergraduate studies at the University of California, Davis.

After expelling their European rivals from the Amazon in the early–seventeenth century, the Portuguese set about exploiting the principal assets of the vast basin—the indigenous inhabitants. As allies, converts, and slaves the native population provided the labor and much of the social fabric of the developing colony. While a variety of canoe-borne expeditions ventured ever farther up the main river and its tributaries seeking elusive gold, harvesting forest products, and expanding the crown's domain, prosperity and power for the leaders and sponsors of those forays derived mainly from the human cargo brought downstream to missions, forts, and other settlements. As a result, crown and colonial authorities attempted to regulate and control the expeditions, and fierce competition developed among institutions and individuals involved in the process. Documents in Portuguese and Brazilian archives reveal the key role played by the Indians themselves in collaboration with the little-studied cross-cultural intermediaries, known as cunhamenas.