The Role of Independent Invention in U.S. Technological Development, 1880–1930

Why did independent inventors account for over half of U.S. patents by 1930 and more than three times the number granted to R&D firms? Using new data on patents and historical patent citations, I show that independents supplied high-quality innovations to a geographically broad market for ideas. Those close to large urban centers developed some of the most significant technological advances. Demand for independent inventions remained high during the growth of the corporate economy as firms continued to acquire external innovations that complemented formal R&D. Despite their relative decline, independents remained central to the process of technological development.