To commemorate the 75th anniversary of the Naval Research Laboratory (NRL), 75 innovations were formally recognized in a ceremony held on June 19, 1998 in Washington, D.C. These innovations were selected to reflect the breadth and the sustained impact of the Laboratorys program. They include some of NRLs most important contributions to science, technology, national security, and society. They are, however, not to be interpreted as the Top 75. While a few are scientific in nature, such as the Nobel Prize-winning work in chemistry, most are technological innovations that have found use in military and/or industrial applications. All are unclassified. Therefore, some major contributions, in areas such as space systems and electronic warfare, could not be publicly recognized. To avoid an overwhelming document, the histories of the 75 were written to be brief. Such brevity means that much of the fascinating story behind each innovation unfortunately remains untold. However, together these 75 histories tell a fascinating story of a 75 year-old laboratory through their simple and individual differences. Some innovations were achieved quickly. In order to meet the national goal of orbiting a scientific satellite during the International Geophysical Year, Project Vanguard pioneered the development of a three-stage rocket, tracking system, and satellite in the unprecedented time of2-1/2 years. Others required many years to bring to fruition. The development of the first U.S. radar spanned the better part of two decades and was fielded in time for duty in the critical Pacific naval battles of World War II. Some were forged in times of war. A massive engineering effort, made in the midst of world conflict, resulted in a new uranium separation process that contributed to the Manhattan Project's success.