Complex sentence: In 1787, Argüello was appointed lieutenant and commandant of the Presidio of San Francisco, serving until 1791 and again from 1796 to 1806, and commandant of the Presidio of Monterey from 1791 to 1796.
Split into simpler sentences: In 1787, Argüello was appointed lieutenant and commandant of the Presidio of San Francisco, serving until 1791 and again from 1796 to 1806. In between he was commandant of the Presidio of Monterey, from 1791 to 1796.