Betances was the fourth of six children; the oldest of which would die shortly after birth; Betances was the only male among the surviving siblings. The family was described as being of mixed race in records of the day. His mother died in 1837, when he was nine years old, and his father remarried in 1839; the five children he had with María del Carmen Torres Pagán included Ramón's half-brother Felipe Adolfo, who was not involved in politics (according to Ramón) but was nevertheless arrested following the Grito de Lares years later.