[1] In 1805, Argüello entered the Spanish Army as a cadet in Yerba Buena (present day San Francisco).
From 1831 to 1835, Argüello was captain of the company and took part, with his brother-in-law Agustín V. Zamorano, in the 1831 revolt against Governor Manuel Victoria.
They sent a committee of five to the presidio commandant to complain of pueblo residents' hunger, lack of clothing, and back pay due - with a demand for payment to them.
[3] From 1838 to 1840 Santiago Argüello was administrator of the Mission San Juan Capistrano, and in 1841 for that service he was granted Rancho Trabuco.
He welcomed the stabilizing influence of the Americans, as the Mexican Alta California government was in disarray after the ouster of Governor Manuel Micheltorena in 1846.
He was a member of the U.S. California military territory legislative council in 1847, and was later made customs collector of the Port of San Diego.