Biographical information on a sample of renowned U.S. inventors is combined with information on the patents they received over their careers, and employed to highlight the implications of patent institutions for markets in inventions and for democratization. The United States deliberately created a patent system that differed from existing European systems in ways that significantly affected the course of technological change. Patent rights in the U.S. helped to define and enforce tradable assets in new technological knowledge. By facilitating access to such markets in technology, patents enhanced the benefits to relatively disadvantaged individuals who might otherwise have been unable to directly extract returns from their technological creativity, and their response to such incentives increased overall technological progress. For this reason, despite the defects of patent monopolies, developing economies today may still advance technological progress and improve social welfare by providing broad access to property rights in inventions.