The John L. Nau III Center for Civil War History at the University of Virginia is pleased to announce Andrew E. Masich’s Civil War in the Southwest Borderlands, 1861-1867 (Oklahoma University Press, 2017) as the winner of the 2018 Bobbie and John Nau Book Prize in American Civil War Era History. In this sweeping narrative, Masich examines the tangled nature of the military conflicts that emerged along the southwestern border in the midst of the Civil War era. Masich’s analysis uncovers the power of martial masculinity in shaping social and military dynamics in the diverse cultures that populated this complex region. This wonderfully written book is a true transnational study, supported by archival work in Mexico as well as the United States, and reflecting a deep understanding of the intertribal and intratribal struggles that emerged in the midst of the American Civil War. Masich explains how the American military conflict helped shape the region, even as those tumultuous years witnessed their own internal conflicts. The prize carries with it a $25,000 award and will be conferred at a dinner at UVA in the fall of 2018.