[3] Chillum, the neighborhood, is contained between the Northwest Branch Anacostia River to the east, East West Highway (MD 410) and the Sligo Creek River to the north, New Hampshire Avenue (MD 650) to the west, and Eastern Avenue NE to the south.

Chillum borders the adjacent communities of Avondale, Green Meadows, and Carole Highlands in Prince George's County as well as the city of Takoma Park in Montgomery County, and the Riggs Park (also known as, "Lamond Riggs"), Queens Chapel, and North Michigan Park neighborhoods of Northeast Washington D.C. Actor Jonathan Banks is from Chillum.

[7] It included lands in the present-day District of Columbia and in Prince George's County, and was composed of previously established land patents such as Henrietta Maria, Widows Purchase, Yarrow and Yarrow Head.

[9] The manor house for the Henrietta Maria parcel was named Green Hill.

It was home to William Dudley Digges and was the place where Pierre L'Enfant, designer of nearby Washington, D.C., died in destitution in 1825.

[9] He remained buried at the Green Hill property until being re-interred at Arlington National Cemetery in 1909.

[10] Since this area was not served by public transportation, such as a streetcar, Chillum remained rural in character into the 1930s.

Beginning in the mid-1930s, the area of Chillum that is close to the District of Columbia border was subdivided into lots.

Developers promoted the area’s convenient access into the city as well as its water, gas, and electricity supply.

The first platted developments in the late 1930s included Chillum Gardens and Oakdale Terrace.

In contrast, the developer-built Green Meadows and Brookdale Manor were platted in the early 1940s and completed by 1942.

Several subdivisions were constructed along Riggs Road, Sargent Road, and Sligo Creek Park in the 1950s, including Sargent Knolls (1950), Bel Air Estates (1955), Parkland (1955), Carrington (1957), and Miller Estates (mid-1950s-early 1960s).

The Chillum Heights Apartments consist of three story brick structures containing a combined total of 1,147 units.

The parent-teacher organization chose Chavez, the school held a public hearing on the matter on January 10, 2000, and the county board approved the name change on March 30, 2000; it was effective fall 2000.

[2][21][22] Carole Highlands Elementary serves parts of the current Chillum CDP.

Chillum Community Park (This park is located at the intersection of Ray Road and Cypress Creek Drive on the far east side of Chillum, located directly west of the Northwest Branch Anacostia River but directly south of the Sligo Creek River.

The following is a list of historic sites in Chillum identified by the Maryland-National Capital Park and Planning Commission:[25] At the 2020 American Community Survey, the CDP was 31.5% Salvadoran, 4% Guatemalan, 3.6% Dominican, 3% Honduran, 2.5% Mexican, .8% Puerto Rican.

[31] However, since the 1990s, the Hispanic/Latino population has significantly increased in Chillum, MD as immigrants from countries all over Central America found plenty of labor/ janitorial/ housekeeping jobs in the Washington D.C. area and an abundance of affordable housing in Chillum, MD that would allow them to commute very easily and conveniently to their jobs.