Quill and Cross in the Borderlands examines nearly four hundred years of history, folklore, literature, and art surrounding the legendary Lady in Blue and her historical counterpart, Sor María de Jesús de Ágreda. This legendary figure, identified as seventeenth-century Spanish nun and writer Sor María de Jesús de Ágreda, miraculously appeared to tribes in colonial-era New Mexico and taught them the rudiments of the Catholic faith. Sor María, an author of mystical Marian texts, became renowned not only for her alleged spiritual travel from her cloister in Spain to New Mexico but also for her writing, studied and implemented by Franciscans and others around the world. Working from original historical accounts, archival research, and a wealth of literature on the legend and the historical figure alike, Anna M. Nogar meticulously examines how and why the person and the legend became intertwined in Catholic consciousness and social praxis. Nogar addresses the influence of Sor María’s spiritual texts on many spheres of New Spanish and Spanish society over several centuries. Eventually, the historical Sor María and her writings virtually disappeared from view, and the Lady in Blue became a prominent folk figure in the present-day U.S. Southwest and U.S.-Mexico borderlands, appearing in folk stories, artwork, literature, theater, and public ritual that survives today. Quill and Cross in the Borderlands documents the material legacy of a legend that has survived and thrived for hundreds of years, and at the same time rediscovers the extraordinary impact of a hidden writer.