The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the National Academy of Medicine (NAM). The National Academy of Sciences is a member of the International Council for Science (ICSU). The NAS was signed into law in 1863, during the Civil War, by President Abraham Lincoln. The academy was created to serve as an official adviser to the federal government on matters of science and technology.