During his career, Bush patented a string of his own inventions. He is known particularly for his engineering work on analog computers, and for the memex.
Starting in 1927, Bush constructed a differential analyzer, an analog computer with some digital components that could solve differential equations with as many as 18 independent variables. An offshoot of the work at MIT by Bush and others was the beginning of digital circuit design theory.
The memex, which he began developing in the 1930s (heavily influenced by Emanuel Goldberg's "Statistical Machine" from 1928) was a hypothetical adjustable microfilm viewer with a structure analogous to that of hypertext. The memex and Bush's 1945 essay "As We May Think" influenced generations of computer scientists, who drew inspiration from his vision of the future.
Bush was appointed to the National Advisory Committee for Aeronautics (NACA) in 1938, and soon became its chairman. As chairman of the National Defense Research Committee (NDRC), and later director of OSRD, Bush coordinated the activities of some six thousand leading American scientists in the application of science to warfare. Bush was a well-known policymaker and public intellectual during World War II, when he was in effect the first presidential science advisor. As head of NDRC and OSRD, he initiated the Manhattan Project, and ensured that it received top priority from the highest levels of government. In ''Science, The Endless Frontier'', his 1945 report to the President of the United States, Bush called for an expansion of government support for science, and he pressed for the creation of the National Science Foundation.