Mechanical engineering is critical to the design, manufacture, and operation of small and large mechanical systems throughout the U.S. economy. This book highlights the main findings of a benchmarking exercise to rate the standing of U.S. mechanical engineering basic research relative to other regions or countries. The book includes key factors that influence U.S. performance in mechanical engineering research, and near- and longer-term projections of research leadership. U.S. leadership in mechanical engineering basic research overall will continue to be strong. Contributions of U.S. mechanical engineers to journal articles will increase, but so will the contributions from other growing economies such as China and India. At the same time, the supply of U.S. mechanical engineers is in jeopardy, because of declines in the number of U.S. citizens obtaining advanced degrees and uncertain prospects for continuing to attract foreign students. U.S. funding of mechanical engineering basic research and infrastructure will remain level, with strong leadership in emerging areas.