In the 1850s, Juana Catarina Romero, known popularly as Juana Cata, peddled her cigarettes on the streets of Tehuantepec in the state of Oaxaca, Mexico, an activity that enabled her to serve as a spy for the liberals under the command of Captain Porfirio Díaz during the War of the Reform (1858–1860). By 1890, Romero (1837–1915) had emerged as an international merchant, sugar cane producer and refiner, philanthropist, and “modernizing” cacica of the city of Tehuantepec. As powerful women rarely receive credit for their achievements, popular myth attributes her success to the men in her life, a supposed youthful love affair with Díaz or a later lover, Colonel Remigio Toledo. In contrast, a study of her career helps to shed light on how women could attain and exercise power in the 19th century and the ways in which they participated in the construction of the nation-state and a capitalist economy. Her trajectory shows that when allied with these forces of modernization, women could take on a more public role in society. It also reveals that it is through the lens of local and regional history that women’s contributions and accomplishments, so often erased in national histories, can be made visible.