María Elena Martínez did not know that she had a rare and aggressive cancer until May 2014. Treatment options for adrenal cancer are few, and when these didn't work out, she fought to be as much herself as possible while the disease took its course. She died at home in Los Angeles on November 16, 2014, surrounded by close friends and family.

María Elena was a proud native of Durango, where she was born in 1966 and grew up in a world of cattle ranches and itinerant schoolteachers, the little sister of four brothers. Her family moved to Chicago during the 1970s, in part to find her better educational opportunities, although they returned regularly to their ranch in Pascuales. She entered Northwestern University in 1984, majoring in Latin American studies (with a concentration in literature) and minoring in women's studies. María Elena remained in Chicago after college and worked with several Latino community organizations, along the way cofounding one herself, LLENA (Latinas Lesbianas en Nuestro Ambiente). She entered the University of Chicago in 1988 and wrote a master's thesis about the legal status of Mexican women in the 1970s. After that, she sought to plot her historical questions about race and gender on a longer chronology and turned her attention to the colonial period; initial archival research in Puebla, and an abiding interest in the Inquisition, led her to write a dissertation under the direction of Friedrich Katz about limpieza de sangre in New Spain. She completed it in 2002, one year after she began teaching at the University of Southern California, first in the Department of History and, eventually, also in the Department of American Studies and Ethnicity.

To remember María Elena and her quick, clear mind is to recognize how important her life trajectory was to her exceptional scholarship, itself focused on origins and genealogy, stories about where people and ideas came from. Her 2004 William and Mary Quarterly essay, “The Black Blood of New Spain: Limpieza de Sangre, Racial Violence, and Gendered Power in Early Colonial Mexico,” remains a fixture on many syllabi and was a forerunner of her obra maestra, the book Genealogical Fictions: Limpieza de Sangre, Religion, and Gender in Colonial Mexico (Stanford University Press, 2008). This was an ambitious project about notions of blood purity and the legal, religious, and procedural forces that gave them power and meaning. Genealogical Fictions was as much a contribution to the field of Spanish history as to Latin American history, and one conscious of the interest by scholars beyond those regions in the history of racism and the making of racial categories. It traced the development of a transatlantic discourse of stain and impurity, flexible and resilient enough to matter from medieval Europe to Mexico.

To write Genealogical Fictions, María Elena immersed herself in the language of hundreds of probanzas submitted by Spaniards seeking high offices. Proving clean lineage by the sixteenth century involved a kind of inquisition: close scrutiny of one's origins to determine whether one's ancestors were reputed to be free of all suspicion of being Jews, Muslims, or heretics. New peninsular converts to Christianity fell outside the boundaries of what was “Old Christian” and pure. In New Spain, as María Elena shows, these concepts were remade and repurposed. While by the early 1600s “black blood” profoundly threatened those trying to maintain colonial order, indigenous Mexican nobles were claiming a heritage that was at once New Christian and distinguished, uncontaminated by heretical, Jewish, or Muslim descent.

Much more could be said about María Elena's landmark study. Genealogical Fictions won the Conference on Latin American History's Mexican History Book Prize and the American Historical Association's James A. Rawley Prize in Atlantic History; it was especially praised by scholars for making gender central to its analysis of shifting categories and ideologies of difference. The book ranges across the entire colonial period of New Spain's history, advancing bold hypotheses in its final chapters about the secularization of colonial society and the emergence of more phenotypical ways of discerning difference in the “age of reason.” She followed up by collaborating with Max S. Hering Torres and David Nirenberg on an edited volume, Race and Blood in the Iberian World (Lit Verlag, 2012). That so many contributors were already following up on arguments put forth in Genealogical Fictions is but one testament to how profoundly María Elena changed the conversation.

María Elena belonged to the editorial board of this journal from 2012, and to that of the Journal of the History of Ideas from 2009. She served as a primary adviser on the 2010 PBS documentary When Worlds Collide, on the early modern Spanish empire. She understood well enough how empires worked that she never sought to build one of her own, but in her understated way she took the lead in shaping the field through innovative combinations of people and ideas. In 2005, María Elena inaugurated the Colonial Latin America seminar for the USC-Huntington Library Early Modern Studies Institute, creating over the years one of the premier forums where colonialists shared ideas. She invited scholars young and old with little regard for policing disciplinary borders, and she had a knack for tailoring events to specific scholars and projects: fancy lectures for newly minted PhDs, informal workshops for interdisciplinary dialogue, big conferences for thorny intellectual questions. She regularly brought Mexican scholars and artists to USC, and she led discussions as director of the Latin American Studies Initiative about integrating Latin American and Latino/a studies at the university.

And then there was her commitment to Mexico. María Elena never considered herself a historian of an “other” part of the world, and since completing a summer program at El Colegio de México in 1991 she imagined her intellectual community as one that spanned the US-Mexican border — and many others. At USC, she organized through the Visions and Voices initiative a series of events featuring Mexican women involved in feminism, art, journalism, theater, and politics. Its highlights included a dramatic reading by Mexican actress and feminist Jesusa Rodríguez of the “Primer sueño” by one of María Elena's enduring favorites, Sor Juana Inés de la Cruz. Most memorably, María Elena was an early and enthusiastic participant in the Tepoztlán Institute for Transnational History of the Americas, an annual gathering in Tepoztlán with the twin goals of fostering transnational studies and enabling conversations between North and Latin American scholars. She codirected the institute during a critical transition period and remained on the organizing collective in subsequent years. It exemplified much of what María Elena valued intellectually — interdisciplinary thinking across national and linguistic divides, rooted in Mexico but always looking beyond it — and her experiences in Tepoztlán steered her work in new and surprising directions.

Recently María Elena was hard at work on a book provisionally titled “The Enlightened Creole Science of Race and Sex: Naturalizing the Body in the Eighteenth-Century Spanish Atlantic World.” It focused on changing ideas about race and sex in Spanish America and Spain, in particular new theories of human difference that emphasized knowledge of the body through observation and through emerging sciences of anatomy, chemistry, and physics. Though she did not get to complete it, she left us with a sense of where she was headed in her extraordinary (and characteristically fearless) essay “Archives, Bodies, and Imagination: The Case of Juana Aguilar and Queer Approaches to History, Sexuality, and Politics” (Radical History Review, fall 2014), about the “hermaphrodite” Juana Aguilar, put on trial by the Real Audiencia and examined in 1803 by the enlightened Dr. Narciso Esparragosa y Gallardo. María Elena, inspired by her collaboration with Jesusa Rodríguez, reflects on the silences of the archives and on how the open-endedness of performance — namely, Rodríguez's work in progress, a one-woman show workshopped at USC in 2013 in which she embodies Esparragosa — can open our historical imaginations.

What more would have come from the mind of a scholar described by one colleague as “righteously uncontainable”? It's heartbreaking that we can only wonder. María Elena lived fully and well; she loved nothing better than a good meal with her friends, a hike up the mountains surrounding Tepoztlán, a game of tennis, or a hangout with Sarah Gualtieri, her partner of many years. We loved her sense of humor and her knack for combining intellectual projects with good fun. And we miss her terribly. We have lost an inspiring colleague and a cherished friend.