Writing from the vantage point of the Texas-New Mexico boundary issue, Mark Stegmaier provides a comprehensive analysis of the dispute, the compromise, and the overall implications for the Civil War. He meticulously examines the crisis through a close reading of Texan and New Mexican documents, U.S. government records, maps, newspapers - particularly the reports of Washington correspondents - and collections of personal letters. In addition, he introduces a revisionist analysis of roll call voting in the U.S. Congress and the Texas legislature. Stegmaier recounts how, with the support of Southern radicals, Texas attempted to extend its jurisdiction despite opposition from New Mexicans and U.S. political leaders. Threatened by military occupation, New Mexicans countered by seeking free state status, while Presidents Taylor and Fillmore committed U.S. forces to defend the territory against a Texan attack. The resolution of this issue allowed the passage of the Compromise of 1850, the last great accord on the sectional issues between North and South. Texas, New Mexico, and the Compromise of 1850 deserves the term "definitive." It will appeal to all students of the Civil War era.