In 1967, Dr. Adrian Kantrowitz performed the first human heart transplant in the United States. Throughout this life he was both a surgeon and a prolific inventor, developing devices such as cardiac pacemakers, mechanical left heart devices, and the intraaortic balloon pump. Dr. Kantrowitz passed away in 2008, and his papers were donated to the National Library of Medicine shortly afterwards. As part of its Profiles in Science Project, the Library has digitized a portion of these papers and included a finding aid and a biographical essay. Users can click on the "All Documents" area to look through all the printed papers, or move along to the "All Visuals" area to view photographs of Kantrowitz at work in a surgical setting and at leisure. The other areas are divided up chronologically, and they include "Expanding Technological Possibilities, 1955-1970" and "Replacing Hearts: Left Ventricle Assist Devices and Transplants, 1960-1970".