Jose de Escandon's colonization work in the present Mexican state of Tamaulipas and the lower Rio Grande valley forms an essential part of the Spanish northern borderlands. Many of the land grants in the area, ranching, and some of the present day agricultural industries originated with the colonization projects initiated by Escandon, who proved himself a capable military leader, administrator, and business person by suppressing several Indian uprisings, by overseeing the missions in his district of Queretaro, and by his prosperous commercial ventures. These achievements led to his appointment in 1746 to head the pacification and settlement of the Seno Mexicano. In 1748 Escandon was chosen governor of Nuevo Santander. As governor Escandon established several settlements in the Seno Mexicano, thus securing the area against foreign threats. This booklet briefly reviews Jose de Escandon's life and accomplishments. Topics covered include: the Northern Spanish frontier, Indians in the Seno Mexicano, early entradas into Seno Mexicano, Escandon's early career, plans for the conquest of the Seno Mexicano, Escandon's appointment as colonizer, Escandon's entrada into the Seno Mexicano, settlement of Nuevo Santander, Jose Tienda de Cuervo Report, general visit of the 1767 Royal Commission, and the end of Escandon's governorship. An 18-item bibliography concludes the booklet. (NQA)