#camanche

The trade then evolved to include not just Hispanic traffickers but horse-mounted Comanche and Ute warriors, who raided the settlements of Apache, Kiowa, Jumano, Pawnee and other peoples. They took captives, many of them children plucked from their homes, and sold them at auctions in village plazas.

The Spanish crown tried to prohibit slavery in its colonies, but traffickers often circumvented the ban by labeling their captives in parish records as criados, or servants. The trade endured even decades after the Mexican-American War, when the United States took control of much of the Southwest in the 1840s.

Seeking to strengthen the 13th Amendment, which abolished slavery in 1865, Congress passed the Peonage Act of 1867 after learning of propertied New Mexicans owning hundreds and perhaps thousands of Indian slaves, mainly Navajo women and children. But scholars say the measure, which specifically targeted New Mexico, did little for many slaves in the territory.

Many Hispanic families in New Mexico have long known that they had indigenous ancestry, even though some here still call themselves “Spanish” to emphasize their Iberian ties and to differentiate themselves from the state’s 23 federally recognized tribes, as well as from Mexican and other Latin American immigrants.

But genetic testing is offering a glimpse into a more complex story. The DNA of Hispanic people from New Mexico is often in the range of 30 to 40 percent Native American, according to Miguel A. Tórrez, 42, a research technologist at Los Alamos National Laboratory and one of New Mexico’s most prominent genealogists.

He and other researchers cross-reference DNA tests with baptismal records, marriage certificates, census reports, oral histories, ethnomusicology findings, land titles and other archival documents.

Mr. Tórrez’s own look into his origins shows how these searches can produce unexpected results. He found one ancestor who was probably Ojibwe, from lands around the Great Lakes, roughly a thousand miles away, and another of Greek origin among the early colonizers claiming New Mexico for Spain.

“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.”

Brienna Martinez performed the Matachines dance in Alcalde, N.M.

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.

Moisés Gonzáles, a Genízaro professor of architecture at the University of New Mexico, has identified an array of Genízaro outposts that endure in the state, including the villages Las Trampas and San Miguel del Vado. Some preserve traditions that reflect their Genízaro origins, and like other products of colonialism, many are cultural amalgams of customs and motifs from sharply disparate worlds.

Each December in the village of Alcalde, for instance, performers in headdresses stage the Matachines dance, thought by scholars to fuse the theme of Moorish-Christian conflict in medieval Spain with indigenous symbolism evoking the Spanish conquest of the New World.

In Abiquiú, settled by Genízaros in the 18th century, people don face paint and feathers every November to perform a “captive dance” about the village’s Indian origins — on a day honoring a Catholic saint.

Miguel A. Tórrez conducts the El Pueblo de Abiquiú DNA and Ethnographic Study, which examines the backgrounds of people who either identify as Genízaros or are descendants of Genízaros in Abiquiú.

“Some Natives say those in Abiquiú are pretend Indians,” said Mr. Tórrez, the genealogist. “But who’s to say that the descendants of Genízaros, of people who were once slaves, can’t reclaim their culture?”

Efforts by some Genízaro descendants to call themselves Indians instead of Latinos point to a broader debate over how Native Americans are identified, involving often contentious factors like tribal membership, what constitutes indigenous cultural practices and the light skin color of some Hispanics with Native ancestry. Some Native Americans also chafe at the gains some Hispanics here have sought by prioritizing their ancestral ties to European colonizers.

Pointing to the breadth of the Southwest’s slave trade, some historians have also documented how Hispanic settlers were captured and enslaved by Native American traffickers, and sometimes went on to embrace the cultures of their Comanche, Pueblo or Navajo masters.

Kim TallBear, an anthropologist at the University of Alberta, cautioned against using DNA testing alone to determine indigenous identity. She emphasized that such tests can point generally to Native ancestry somewhere in the Americas while failing to pinpoint specific tribal origins.

“There’s a conflation of race and tribe that’s infuriating, really,” said Ms. TallBear, a member of the Sisseton Wahpeton Oyate tribe of South Dakota who writes about tribal belonging and genetic testing. “I don’t think ancestry alone is sufficient to define someone as indigenous.”

The discovery of indigenous slave ancestry can be anything but straightforward, as Mr. Trujillo, the former postal worker, learned.

First, he found his connection to a Genízaro man in the village of Abiquiú. Delving further into 18th century baptismal records, he then found that his ancestor somehow broke away from forced servitude to purchase three slaves of his own.