The US national weather service began in 1870 as an Army Signal Service telegraph operation

According to the National Weather Service's official history timeline (weather.gov), the first US national weather-warning system was created not as a civilian scientific agency but as a military telegraph operation. A joint congressional resolution directed the Secretary of War to provide for taking meteorological observations at the interior military stations and "for giving notice on the northern lakes and on the seacoast, by magnetic telegraph and marine signals, of the approach and force of storms." President Grant signed the resolution on 9 February 1870.

The new service was housed inside "the U.S. Army Signal Service's Division of Telegrams and Reports for the Benefit of Commerce." Its first synchronized observations — from 24 stations, transmitted by telegraph with Western Union's cooperation — were taken on 1 November 1870. The weather service was thus, for its first two decades, an Army command that ran on the same telegraph network built out during and after the Civil War.

This places the founding of American weather forecasting squarely in the manual-telegraphy era that the vault already documents through claim-telegraphists-cramp-1890s-classified-as-occupational-neurosis: the same wires and Morse-operator labor force that produced an occupational-health epidemic among telegraphists also carried the nation's first storm warnings. The institution's military parentage set up two later transitions recorded separately — the appointment of an Arctic-disaster survivor as director (claim-greely-arctic-disaster-survivor-ran-us-weather-bureau-1887-1891) and the 1890–91 move to civilian control (claim-1890-91-weather-service-transferred-to-agriculture-at-harrisons-request).