Washington is known as a city of neighborhoods. Slowly developed and transformed over 200years, Washington's neighborhoods number well over 100, reflecting the kaleidoscope of the District of Columbia's history.

Georgetown, Washington's earliest neighborhood, began as an independent entity founded by Scots in 1752, at the mouth of Rock Creek on the Potomac. Forty years later the president of the United States, George Washington, included Georgetown in the new federal city. The diamond-shaped district incorporated Alexandria and Arlington (given back to Virginia in 1846) on the opposite bank of the Potomac and several miles downstream, as well as two "paper towns," platted but never developed (Hamburg in today's Foggy Bottom and Carrollsburg at Buzzard Point).

The City of Washington, as originally established, encompassed the section of the District below Florida Avenue (then Boundary Street) and above the Potomac and Anacostia—a shallow bowl ringed by hills. Settlements began at the centers of employment (the White House, Capitol, Navy Yard, and adjacent to Georgetown). Development slowly filled in L'Enfant's plan—not before wags called Washington the city of "magnificent intentions"—underlining intentions unfulfilled.

Suburbs to the city began to sprout—1854 Uniontown (now Anacostia) was founded for Navy Yard and St. Elizabeth's Hospital workers. In the 1860s development jumped unto the heights above the city (Mount Pleasant). Nestled right next to the city boundary, LeDroit Park was assembled and developed in the 1870s. The neighborhoods south of the convention hotels, across the 1906 Taft Bridge, Dupont Circle and Kalorama (formerly Washington Heights) filled in during the 1880s.

At the end of the 19th century, real estate development intensified, exploding out along the travel routes to adjacent Maryland. The city flowed out of the bounds of the L'Enfant plan. Developers extended the railroad and streetcar lines (begun in 1860) to bring government workers to new "suburban" housing tracts. Connecticut Avenue was driven straight out to the Maryland state line (taking into account existing Washington Heights development). Woodley Park, the neighborhood adjacent to the conference hotels, began as a turn-of-the-century streetcar suburb of eclectic single-family homes, as did Cleveland Park, Friendship Heights, and Chevy Chase. Since 1854 over 125 subdivisions had been created in a crazy-quilt patchwork. District authorities and Congress saw the need to coordinate this suburban development, which was expensive to pave and provide with utilities. After extensive debate and litigation, Congress passed, repealed, and re-passed legislation (in effect to this day) establishing the District's permanent system of highways. The new highway system extended the L'Enfant plan's grid (and a few diagonal avenues). Some of the "mis-fit subdivisions" were grandfathered in (e.g. LeDroit Park, Marshall Heights, Woodridge), but the effect was to propagate the grid to the District boundary—essentially subdividing the District in its entirety. While amended over time to fit more closely to the topography, the highway system was the grid into which all future subdivisions fit.

Like some SimCity game, the grid was slowly filled in. New neighborhoods spread out and old ones changed. Catholic University grew hand-in-hand with its surrounding Brookland neighborhood—numerous Catholic religious and educational institutions creating "Little Rome." American University was similar in fostering American University Park, American University Heights, and Wesley Heights. A systematic zoning plan emphasizing mixed uses and nodes of commercial development spanned Cleveland Park with a mix of apartment residential and commercial development. K Street, once lined with fine houses, became a commercial area solidly filled with glass office boxes of 1970s–2000s vintage.

Racial composition of neighborhoods shifted as the 20th century dawned. In the 19th century, African Americans had lived in the city and also scattered in smaller neighborhoods based on post-Civil War settlements at fort sites. Beginning in the 1890s, well-to-do African Americans moved into the originally exclusively white suburb of LeDroit Park, which became majority black by World War I. East of the river, Anacostia and its sibling neighborhoods, long primarily white, became majority black. Georgetown, itself divided into informal neighborhoods, some with a strong black population and heritage, gentrified with the New Deal and the subsequent war years, and the black population dropped. Southwest Washington, one of the oldest neighborhoods in the District, was transformed by model urban redevelopment in the 1950s and 1960s. The southwest had been a neighborhood of rich diversity, with African American, white, and Jewish populations (Al Jolson was born there). African Americans displaced by redevelopment moved elsewhere in the District and its suburbs. The District's population peaked in the 1950s and shifted to majority black by 1960. Much of the city's grid was developed and population flowed to the suburbs in the neighboring counties.

The District's neighborhoods reflected in part this change, but the 1980s saw the influx of a Hispanic/Latino population, changing the look of the Adams Morgan and Mount Pleasant neighborhoods across the Duke Ellington Memorial Bridge from the convention hotels. U Street, which had been the heart of the African American community, began to be redeveloped in the 1980s. Neighborhood development returned to its origin in the late 1990s and early 2000s, as sections of the east end of downtown redeveloped as residential areas, including Penn Quarter near the Capitol and NoMA, Massachusetts Avenue near Union Station.

—Matthew Gilmore of New Light Technologies is editor of H-DC.