The dashed rust-colored line on the map isn't decoration — it's the boundary of the federal district as it was actually surveyed in 1791, before part of it was ever called Washington, DC.
The Residence Act of 1790 authorized a federal district "not exceeding ten miles square" — a true 100-square-mile square, rotated so its corners point north, south, east and west rather than its sides, which is why it reads as a diamond. Maryland ceded the larger portion (roughly 69 square miles) — all of present-day DC. Virginia ceded the smaller portion (roughly 31 square miles) — Alexandria City and what is now Arlington County. Andrew Ellicott led the 1791–92 survey; Benjamin Banneker assisted with the astronomical observations used to fix the survey's reference lines, spending about three months at Jones Point in Alexandria before leaving the project due to illness. Their crews placed 40 sandstone boundary markers around the full diamond; 36 are known to survive today, several on the National Register of Historic Places.
In 1846, Congress retroceded the Virginia portion back to Virginia. The real, documented reasons were mixed: Alexandria's decline as a port under federal restrictions it couldn't vote to change; the district's residents having no representation in Congress; and, seriously, concern among some Alexandria merchants involved in the domestic slave trade that a more antislavery Congress might restrict or abolish it within the federal district. A Virginia referendum followed in September 1846 — the city of Alexandria voted strongly in favor (763–222), while the surrounding rural county, the future Arlington, voted against it (106–29). Virginia's legislature formally accepted the return in March 1847. Whether the retrocession was even constitutional was disputed at the time and has never been definitively resolved by the Supreme Court on the merits — historians still treat it as a genuinely unsettled legal question, not a closed one.
It's tempting to connect this directly to today's "DMV" (DC-Maryland-Virginia), but that would overstate the link. The original district genuinely did span both Maryland and Virginia, which is a real historical fact worth knowing. But "DMV" as regional slang is a modern coinage, documented as emerging from DC's go-go music scene around the 2000s, with no direct etymological connection to the 1791 cession or 1846 retrocession. Both things are true at once: the region's three-jurisdiction identity has real 18th-century roots, and the specific term people use for it today is much younger and unrelated in origin.
No single published source gives precise coordinates for all four corners of the original square — only for individual surviving boundary stones. The diamond shown here is calculated from two well-documented facts (the district was exactly 10 miles per side, and its south corner was the verified Jones Point site in Alexandria), not pulled from a single authoritative survey overlay. Treat it as a close approximation, not a precise historical GIS record.
Sources: Residence Act of 1790; National Park Service (Jones Point, Banneker); Boundary Stones (WETA); Wikipedia's well-cited "District of Columbia retrocession" article; Washingtonian magazine on the origin of "DMV" as slang.
The economics, education and health figures in this Atlas are shown together deliberately, not as three separate add-ons. That structure is borrowed directly from two real books by W.E.B. Du Bois.
Du Bois personally conducted a door-to-door survey of roughly 2,500 households in Philadelphia's Seventh Ward, over 5,000 interviews in all. The resulting book moves through history, population, education, occupations and economics, health, family, civic life, crime, and housing — in that order — treating them as facets of one social condition rather than separate stories. He graded each surveyed block by social condition and had it hand-colored onto a real fold-out map of the ward, a technique borrowed from Charles Booth's London poverty maps. His conclusion: what looked like a single "Negro problem" was actually, in his words, "a plexus of social problems" — produced by discrimination and restricted opportunity, not innate racial traits. Widely regarded as the first empirical sociological study of a Black urban community in the United States, predating the Chicago School by two decades. Read the full text at Internet Archive.
Seven years later, Du Bois led the Eleventh Atlanta University Conference, drawing on census vital statistics, records from 34 life insurance companies, correspondence with Black physicians, and anthropometric measurements of about 1,000 Hampton Institute students. Its finding: "the present differences in mortality seem to be sufficiently explained by conditions of life," and physical measurement showed no basis for claims of biological racial inferiority. He showed that poor white residents of the same Northern cities had tuberculosis rates as high as or higher than Black residents — evidence that condition, not race, drove the gap. Read the full text at Internet Archive.
The structure — a real historical document, paired with what the numbers actually show today — follows how The Marshall Project connected a 1910 medical-education policy (the Flexner Report) to today's Black mortality gap. To be direct about it: no prior scholarship or journalism has paired Du Bois's 1899 and 1906 books with today's Census, Opportunity Insights and CDC data the way this Atlas now does — that pairing is this project's own synthesis, built on real, independently verifiable data, not a claim we found already made elsewhere.
Economics figures are from Opportunity Insights & the U.S. Census Bureau. Education figures are from the Census Bureau's American Community Survey. Health figures are from the CDC/NCHS Small-Area Life Expectancy Estimates Project, with citywide context from peer-reviewed public health research. None of it describes the specific historical people or events documented at a site — it describes the neighborhood today.
This is a walkable-avatar prototype built on top of the Frankly Inspired Institute Washington DC Atlas dataset. It uses the same real, sourced places already documented in the Atlas — you move an avatar through real Washington DC geography and discover them as you go, instead of seeing every marker at once.
The map covers the full original 1791 federal district, not just present-day DC, including several real sites in Alexandria and Arlington that were once literally part of Washington. Tap "The Original District" above to see why.
This is an R&D pilot asset, not a reviewed public historical publication. All place content is drawn from the existing Atlas dataset and carries the same sourcing and evidence-status distinctions used there.
FII evidence status
Prototype note: evidence status describes FII review readiness. It does not mean that an official historic designation automatically equals FII publication approval.
Neighborhood data, when shown
Some places also show real, present-day Census-tract statistics from Raj Chetty's Opportunity Atlas (Opportunity Insights & the U.S. Census Bureau) — income and incarceration outcomes for children who grew up in that same neighborhood, decades after the history documented there. It is data about a place today, not about the historical people or events at that site.
Simulation control only. Enabling this button is not school, parent, guardian, institutional or publication authorization.
No place in the Atlas dataset is documented here yet. Use your camera to record what's here, then describe what you think it is — the same "unfinished archive" idea already built into this Atlas, just done with a real camera instead of clicking a spot on the map.
Pilot lock: field photography and video are off by default. A real school deployment requires the applicable school approval, consent, privacy, retention and data-handling rules before capture is enabled. When enabled for an adult-supervised prototype demonstration, a submission remains a Lead and is not public history.