City history
Established on ancestral Nacotchtank land, Washington DC evolved from a surveyed federal capital into the operational heart of American timekeeping and GPS synchronization.
Chapter one
Indigenous name
"Town of traders"
The Nacotchtank people maintained a major trading settlement near the confluence of the Anacostia and Potomac rivers. English explorer John Smith recorded the village during his 1608 expedition. Jesuit missionaries and European settlers later Latinized the name to Anacostan or Anacostine.
Town of traders
The ancestral Algonquian village located along the Anacostia River, documented by Captain John Smith in 1608.
Land honoring Christopher Columbia
Created by Congress under the Residence Act of 1790 to serve as the nation's federal capital district.
Named in honor of George Washington
Designated by the founding commissioners as the central planned municipality within the federal territory.
Federal district of America
The District of Columbia Organic Act of 1871 unified Washington, Georgetown, and Washington County into a single municipal entity.
Chapter two
Washington DC abandoned Washington Mean Time and adopted Eastern Standard Time based on the 75th meridian west.
Delegates from 25 nations met in Washington DC and selected Greenwich, England as the international prime meridian.
Congress codified standard time zones into federal law and established the first national Daylight Saving Time during World War I.
Year-round Daylight Saving Time, known as Eastern War Time, was mandated nationwide to conserve energy for national defense.
Congress standardized the official start and end dates of Daylight Saving Time across participating states and federal territories.
Federal law extended Daylight Saving Time to begin on the second Sunday in March and end on the first Sunday in November.
Chapter three
Free Black astronomer Benjamin Banneker and surveyor Andrew Ellicott conducted astronomical observations to establish the ten-mile diamond boundary of the District.
The US Naval Observatory installed America's first time ball atop its telescope dome, dropping it daily at noon to calibrate ship chronometers.
The US Naval Observatory established its Time Service Department, broadcasting precise astronomical time signals across the United States.
Following international adoption of the atomic second, the US Naval Observatory deployed an ensemble of atomic clocks that now anchors GPS precise time.
The US Naval Observatory revived its historic time ball tradition for the White House Millennium Program, dropping a time ball at midnight on New Year's Eve.