U.S. War Deparment "War Department Weather Map"

U.S. War Department. "War Department Weather Map."

U.S. War Department. New York. February 7, 1873. Lithograph. 14 x 22 (neat lines) plus full margins. Archival repairs filling area of center fold with some rivers drawn in. Well preserved map. 

An unusual and highly evocative map published by the U.S. Government to support commerce and industry, boldly noting that “all observations [are] made at the same moment of actual (not local) time.” This printed weather map represents an early predecessor to the real-time forecasts we now receive instantly via television and the internet. Cities across the country are color-coded to indicate conditions such as clear, cloudy, fair, rain, and snow, with arrows illustrating wind direction. Ocean currents in the Atlantic and Pacific are shown with both velocity and direction, while major rivers and elevations—key influences on weather patterns—are selectively detailed.

The map reflects a fascinating collaboration between the U.S. Army Signal Service Office (later the Signal Corps) and the Equitable Life Assurance Society, which prominently lists its address at 120 Broadway, New York City, inviting readers to obtain further information. Intended for immediate, short-term use, examples like this were typically discarded after a single day, making surviving copies potentially very scarce. Beyond its practical function, the map captures a pivotal moment in American history—when emerging science, government infrastructure, and the ambition to understand and control vast land and sea territories converged as the United States completed its continental expansion.