Researching Building History

Use this chart to identify which side of the street even and odd addresses will be on by quadrant. As you walk away from any Capitol Street, even numbers will be on your left and odd numbers will be on your right.

Use the chart below to identify the nearest alphabetic cross-street for the hundred block of a numbered street.

• For example, the 1100 block of 8^th street starts at 8^th and L Street.

• Note that J is omitted from the list of alphabetical streets and that this rule may not apply to streets which are non-continuous such as 8^th etc. 

Modern street addresses do not correspond to the street numberings of buildings in pre-Civil War Washington. The present system of numbering the buildings in Washington City (quadrant system) was developed and implemented in 1869.

Until 1854:  No street numbering.  For example, the store of Charles Sioussa, plasterer, is listed in the1846 city directory as on the west side of 18^th Street, west, between H and I Street, north (i.e., west and north of the Capitol Building)

1854-1869:  As described in the 1867 city directory, address numbers start at the western or northern boundaries of the “City of Washington.” 

Numbers on the lettered streets start at the west on Boundary Street (Florida Avenue), Rock Creek, or the Potomac River, increasing to the east.

Numbers on numbered streets start at the north on Boundary Street, increasing to the south.

Numbers on the diagonal avenues start at Boundary Street, increasing to the southwest or southeast.

e.g.  In 1867, the address of the store of Charles Sioussa, plasterer – on the same site as listed above – was 361 18^th Street, west (i.e., west of the Capitol)

1854-1884:  As described in the finding aid included in the 1867 city directory, Georgetown addresses start at Rock Creek, increasing to the west; and at the Potomac River, increasing to the north.

1884: First city directory in which Georgetown numbering system matches that of the rest of the District of Columbia.

1869-present:  New system devised by E. Dwight Clapp and adopted by the city aldermen and Common Council on November 29, 1869.  Building addresses are based on the progression of the numbered streets and of the lettered streets, and on the quadrants centered at the Capitol, originated by Pierre L’Enfant. 

For example, using the city grid laid out by L’Enfant, Clapp designated the addresses between 3^rd and 4^th, or C and D Streets in the 300 category; and those between 4^th and 5^th, or D and E Streets, in the 400 category. 

Addresses on an Avenue are handled the same way, based on its inclination relative to the horizontal. Maryland Avenue, for example, is at a low inclination; its addresses are as if it were a lettered street. New Hampshire Avenue, with a steep inclination, has addresses like a numbered street. 

Odd address numbers are on the right as one faces in the direction away from the street’s origin. Numbered streets originate at the Mall or East Capitol Street; lettered streets originate at North or South Capitol Street.

Adapted, Original source: “Washington City, Its Founding and Development” by Frederick L. Fishback in Records of the Columbia Historical Society. Vol. 20 (1917).

These downloadable forms can help you keep track of the research you do at the Kiplinger Research Library, online, and at other repositories.