The portion of Bostonia that lies outside the El Cajon city limits is classified as a census-designated place (CDP) for statistical purposes by the United States Census Bureau.

[3] In 1898, David G. Gordon was appointed postmaster in Bostonia to replace Joseph Donald, who had resigned.

[7] In that same year, civic leaders in Bostonia planned to name a local observation as "Grape Day" which led some in neighboring Escondido to complain that their city already had an event under the same name.

[8][9] "Firebugs" believed by Sheriff Conklin to have been members of the Industrial Workers of the World, "German sympathizers" or "disgruntled employees," torched the Meridian School building, a large packing house and two stables of the Bostonia Fruit Growers and Packers Association on October 6, 1917.

[10][11][12][13] Sheriff's deputies engaged in a short gun battle in Bostonia and captured a suicidal man who had threatened a bank in Lakeside, California, with ten pounds of dynamite and fled with his loot.

[14][15] In May 1953 residents of the southern portion of Bostonia approved annexation to the city of El Cajon, California, by a vote of 315 to 271.

They said the weekend operation had grown beyond the "small-time affair it once was," turning the usually quiet area into a "mob scene.

El Cajon Fire Chief Art Melbourne said that Bostonia firefighters did give help but declined to say exactly what it was.

[20] El Cajon Fire Chief Roger House said that Bostonia was not part of any agreement because it did not meet the requirements for belonging, including round-the-clock staffing and a certain kind of equipment.

[22] The center of the community is near the intersection of North 2nd Street and Broadway in the city of El Cajon.

However, the census-designated place of Bostonia is entirely outside the city limits of El Cajon, in an unincorporated area of County.

[23] This is approximately one mile northwest of where the USGS places Bostonia, near the geographic center of the CDP.

Most populations of Ambrosia pumila in Bostonia grew on vacant lots, backyard strips, and gravel roads, and many since have been extirpated by development.

Additionally, Artemisia palmeri, a sagebrush nearly endemic to San Diego County, was once found in the neighborhood.

[24] Other plants historically collected from Bostonia include Primula clevelandii,[25] Sidalcea malviflora,[26] Sisyrinchium bellum[27] and Viola pedunculata.

[28] The statistics below include only the census-designated place, not the part of Bostonia within the city limits of El Cajon.