Immunologist Ralph M. Steinman (1943–2011) was affiliated with The Rockefeller University for 41 years. In 1973, he discovered the seminal cells in the immune system that he named dendritic cells. Steinman then pioneered methods to identify, isolate, and grow dendritic cells and demonstrated they both initiate the immune response and regulate immune tolerance. He laid the foundation for numerous approaches to treat cancer, infectious diseases, and disorders of the immune system, as well as to develop new vaccines. For this body of work, Steinman was a recipient of the Nobel Prize in Physiology or Medicine in 2011. This digital archive contains the University’s last web pages from the Steinman Laboratory (2011). These materials provide a history of the dendritic cell discoveries, key scientific articles and reviews, a scientific biography of Steinman, and the ongoing laboratory member projects, plus a large selection of dendritic cell images and videos. Together, these pages document both the historical and state-of-the-art research that has changed the science of immunology. These web pages were written and illustrated by Steinman with members of his laboratory, in particular Carol L. Moberg and Judy Adams. There is also a complete bibliography of Steinman as well as a scientific appreciation article, remembrances by his closest colleagues, and a copy of the first report of the 1973 dendritic cell discovery.