United States Weather Bureau (1890 - 1970), the primary U.S. government agency tasked with weather-related research and forecasting, was the predecessor to today's National Weather Service. The bureau grew out of the Weather Bureau of the United States, originally created in 1870 and placed under the U.S. Signal Service within the Department of War. It grew and developed in the following years, going through name changes and being reassigned to the Department of Commerce, then the Department of Agriculture (in 1890, adopting its ultimate name), and returning to the Department of Commerce (in 1940). Over the course of its existence, the bureau became increasingly focused on and adept at providing warnings and forecasts, the basis for present-day hurricane, wildfire, flood, and other weather related warning systems (it only developed tornado warning systems relatively late, in the 1950s). In 1966, the bureau was placed under the Environmental Science Services Administration, which in 1970 became the National Oceanic and Atmospheric Administration, at which point the bureau was renamed the National Weather Service.