[6] Callejones was in Spain's gazetteers[7] until Puerto Rico was ceded by Spain in the aftermath of the Spanish–American War under the terms of the Treaty of Paris of 1898 and became an unincorporated territory of the United States.

In 1899, the United States Department of War conducted a census of Puerto Rico finding that the population of Callejones barrio was 2,152.

Barrios (which are, in contemporary times, roughly comparable to minor civil divisions)[14] and subbarrios,[15] in turn, are further subdivided into smaller local populated place areas/units called sectores (sectors in English).

An archeological site consisting of a batey (a large clearing where ceremonies took place) is located in Callejones.

[20] It is of the Early Ostionoid (pre-Taino) (AD 600–1200) and Late Ostionoid (Taino) (AD 1200–1500) prehistoric eras and has been researched by Jose Oliver, a researcher from Yale University,[21] and Samuel Kirkland Lothrop.