context: As early as the late 1820s and early 1830s, she and her sister began opening infant schools in northeastern Ohio.
source: After obtaining a degree from Oberlin College in 1840s, Cowles began a formal career as a teacher.
reference_original: Después de obtener un título en Oberlin College en 1840, Cowles comenzó una carrera formal como maestra.
reference_flipped: Después de obtener un título en Oberlin College en 1840, Cowles comenzó una carrera formal como maestro.