José Campeche made this portrait of Isabel O’Daly (1772−1840) when she was thirty-six years old. Isabel was the daughter of Thomas O’Daly, an Irish engineer who came to San Juan in 1765 to complete the massive fortifications of the city. Campeche had a gift for painting the effects of light and shadow, and his naturalistic modeling captured the indentation above Isabel’s upper lip and the prominence of her chin.