José Cassiano, patriot, merchant, and landowner, was born Giuseppe Cassini in San Remo, Italy, the son of Geronimo and Catalina Cassini. As a young man he became an experienced seaman. He arrived in New Orleans on November 20, 1816, with a British passport, as a resident of Gibraltar. In New Orleans he became a successful merchant and property owner. In connection with his business he made frequent trips to Texas and sometime in the 1820s moved to San Antonio, where he opened a store. He acquired extensive property in San Antonio and landholdings throughout South Texas.
During the siege of Bexar in December 1835 his home and store with its supplies were turned over to the revolutionary army. In 1835–36 he served as a scout along the Rio Grande. Just before the attack on the Alamo he sent messages to William B. Travis on the movements of Antonio López de Santa Anna. He made substantial contributions to finance the revolution. His aid to the cause of independence was recognized when Thomas J. Rusk, secretary of war, issued instructions on June 21, 1836, that Cassiano be permitted to travel freely between Texas and the United States.
Cassiano served as alderman in San Antonio in 1839–40, 1841–42, and 1845–46. He contributed generously to San Fernando de Béxar Cathedral. He was married successively to Josefa Menchaca; Gertrudis Pérez (Peres) de Cordero, widow of Governor Manuel Antonio Cordero y Bustamante; Margarita Valdez in 1833; and Trinidad Soto in 1842. He had three children. The first Cassiano homestead in San Antonio was the old Juan Ignacio Pérez property on Dolorosa Street between Main and Military plazas. Both there and at their ranch, Calaveras, the Cassianos extended hospitality to newly arriving Americans in the early days of the Republic of Texas. Among them were Samuel A. Maverick and his family, who spent their first few months in San Antonio as guests of the Cassianos. Cassiano died on January 1, 1862, and is buried in San Fernando Cemetery in San Antonio.