Manuel Mascareñas, Sr. was a cattle rancher and politician in Sonora, Mexico. He served as president and consul of the municipality of Nogales, Mexico. His son, Manuel Mascareñas, Jr. was a prominent businessman in Sonora. Collection includes a ledger, cash book, invoice book, lettercopy book, legal documents, photographs, newspapers, and miscellaneous personal materials. Chiefly business records of a general merchandise store in Hermosillo, 1884-1891, and legal documents from Arizpe, Sonora, 1847-1851. Family papers include correspondence, awards and medals, and financial papers. Newspapers contain material on Sonoran events including an August 1896 attack on Nogales, Sonora by insurgents, known as "Teresistas," or followers of the healer, Teresa Urrea. Photographs include captured prisoners following the raid and one portrait of Teresa Urrea.