With her sister Mary, in 1823 Catherine Beecher founded a school for girls in Hartford, Connecticut, aimed at training women to become mothers and teachers. Some of the subjects she hoped to teach Beecher had not yet learned herself: her brother Edward then was head of the Hartford Latin School, and she started taking lessons in Latin with him only weeks before she began teaching it. Her students performed excellently at the yearly exhibitions and surprised the many people who did not expect girls to do well. In most female schools of that era, students were expected to learn little more than the fine arts and languages, but Beecher combined a solid core of courses in algebra, chemistry, history, Latin, philosophy and rhetoric. In her 1829 essay, “Suggestions Respecting Improvements in Education,” Beecher wrote: For the brothers of a family the well-endowed college, with its corps of professors, each devoted to one department of knowledge, and with leisure to perfect himself in it and teach it in the most complete manner – for the sisters of the family only such advantages as they could get from one teacher in one room, who had the care of teaching in all branches… As the movement to improve educational opportunities for women gained ground, Beecher’s school began to attract so many students that it was hard to accommodate them all. She successfully sought donations and expanded her school to become Hartford Female Seminary, hiring eight teachers who focused on a few subjects so that each was taught in a “complete manner.” Beecher was also a pioneer in physical education for females. Believing that girls ruined their health with tight corsets, poor diets and culturally-imposed fragility, she introduced calisthenics into the curriculum. She often had visitors who wanted to open similar schools; many graduates of Hartford Female Seminary went on to teach in these schools. She also wrote textbooks used in her school and in those that emulated it. The institution was very successful, and Beecher became a popular and respected figure in Hartford. Her accomplishments and her growing reputation as a talented teacher inspired Beecher to write about her educational philosophy. She believed that the primary goal of education should be to provide a basis for the development of the student’s conscience and moral makeup. She attempted to hire an associate principal to manage this kind of instruction in her school. Beecher believed her school could change the world, and wanted the best female educators available. She approached Mary Lyon (who would found Mount Holyoke Female Seminary in 1836) and then her associate Zilpah Grant to join her as instructors at Hartford Female Seminary. Lyon and Grant both declined. At the same time she was appealing to Grant to serve as associate principal, Beecher was also appealing to Hartford’s rich elite to put the seminary on firm footing. She sought $22,000, arguing that a permanent seminary would draw at least that much to Hartford each year from the new students it would attract. These elite, however, was unwilling to risk investing when no well-known educator would fill the new position. Consequently, Beecher suffered a nervous breakdown and left the school in the hands of her sister for several months while she recovered. Upon her return, she took on the task of religious and moral instruction herself.

Coa súa irmá Mary, en 1823, Catherine Beecher fundou unha escola para nenas en Hartford, Connecticut, destinada a formar ás mulleres para converterse en nais e profesoras. Algunhas das materias que esperaba ensinar a Beecher aínda non se aprendían a ela mesma: o seu irmán Eduardo daquela era xefe da Hartford Latin School e comezou a tomar clases de latín con el só unhas semanas antes de que comezase a ensinalo. Os seus estudantes realizaron unha excelencia nas exposicións anuais e sorprenderon a moita xente que non esperaba que as mozas o fixeran ben. Na maioría das escolas femininas daquela época, esperaba que os estudantes aprendesen pouco máis que belas artes e idiomas, pero Beecher combinou un sólido núcleo de cursos en álxebra, química, historia, latín, filosofía e retórica. No seu ensaio de 1829, "Suxestións sobre melloras na educación", Beecher escribiu: Para os irmáns dunha familia o colexio ben dotado, co seu corpo de profesores, cada un dedicado a un departamento de coñecemento e con lecer para perfeccionarse nel e ensinarllo do xeito máis completo - só para as irmás da familia. Tales vantaxes poden obter dun profesor nun cuarto, que tivo o coidado de ensinar en todas as ramas ... Cando o movemento para mellorar as oportunidades educativas para as mulleres gañou terreo, a escola de Beecher comezou a atraer a tantos estudantes que era difícil acomodalos a todos.Ela buscou con éxito doazóns e expandiu a súa escola para converterse no Hartford Women Seminary, contratando a oito profesores que se centraron nalgunhas materias para que cada unha se ensinase dun xeito "completo". Beecher tamén foi un pioneiro na educación física para as mulleres. Crendo que as nenas arruinaban a súa saúde con corsés axustados, dietas pobres e fraxilidade imposta culturalmente, introduciu a calistenia no currículo. A miúdo tiña visitantes que querían abrir escolas similares; moitos graduados do Seminario Feminino de Hartford continuaron a ensinar nestas escolas. Tamén escribiu libros de texto usados ​​na súa escola e nos que a emulaban. A institución tivo moito éxito e Beecher converteuse nunha figura popular e respectada en Hartford. As súas realizacións e a súa crecente reputación como talentosa profesora inspiráronse a Beecher a escribir sobre a súa filosofía educativa. Ela cría que o obxectivo principal da educación debería ser proporcionar unha base para o desenvolvemento da conciencia e maquillaxe moral do estudante. Intentou contratar a un director asociado para xestionar este tipo de instrucións na súa escola. Beecher cría que a súa escola podería cambiar o mundo e quería ás mellores educadoras dispoñibles. Ela achegouse a Mary Lyon (que atoparía o Seminario Feminino Mount Holyoke en 1836) e logo á súa compañeira Zilpah Grant para unirse a ela como instrutoras no Seminario Feminino de Hartford. Lyon e Grant rexeitaron.Ao mesmo tempo que apelaba a Grant para que actuase como director asociado, Beecher tamén apelaba á rica elite de Hartford para poñer o seminario en pé. Ela buscou 22.000 dólares, argumentando que un seminario permanente atraería polo menos tanto a Hartford cada ano dos novos estudantes que atraería. Non obstante, esta elite non estaba disposta a arriscarse en investir cando ningún coñecido educador ocuparía o novo posto. En consecuencia, Beecher sufriu unha crise nerviosa e deixou a escola en mans da súa irmá durante varios meses mentres se recuperaba. Á súa volta, asumiu a tarefa de instrución relixiosa e moral a si mesma.