“I have Navajo, Chippewa, Greek and Spanish blood lines,” said Mr. Tórrez, who calls himself a mestizo, a term referring to mixed ancestry. “I can’t say I’m indigenous any more than I can say I’m Greek, but it’s both fascinating and disturbing to see how various cultures came together in New Mexico.”

Revelations about how Indian enslavement was a defining feature of colonial New Mexico can be unsettling for some in the state, where the authorities have often tried to perpetuate a narrative of relatively peaceful coexistence between Hispanics, Indians and Anglos, as non-Hispanic whites are generally called here.

Pointing to their history, some descendants of Genízaros are coming together to argue that they deserve the same recognition as Native tribes in the United States. One such group in Colorado, the 200-member Genízaro Affiliated Nations, organizes annual dances to commemorate their heritage.

“It’s not about blood quantum or DNA testing for us, since those things can be inaccurate measuring sticks,” said David Atekpatzin Young, 62, the organization’s tribal chairman, who traces his ancestry to Apache and Pueblo peoples. “We know who we are, and what we want is sovereignty and our land back.”

Some here object to calling Genízaros slaves, arguing that the authorities in New Mexico were relatively flexible in absorbing Indian captives. In an important distinction with African slavery in parts of the Americas, Genízaros could sometimes attain economic independence and even assimilate into the dominant Hispanic classes, taking the surnames of their masters and embracing Roman Catholicism.

Genízaros and their offspring sometimes escaped or served out their terms of service, then banded together to forge buffer settlements against Comanche raids. Offering insight into how Indian captives sought to escape their debased status, linguists trace the origins of the word Genízaro to the Ottoman Empire’s janissaries, the special soldier class of Christians from the Balkans who converted to Islam, and were sometimes referred to as slaves.