Brown married Samuel Charles Blackwell of Cincinnati, Ohio, on January 24, 1856. Mr Blackwell was a businessman and the brother of Elizabeth Blackwell, the first woman in the United States to graduate from medical school. Brown would later become family with her good friend Lucy Stone, a renowned feminist reformer with whom Mrs Brown Blackwell had been friends while at Oberlin College. Her husband’s brother, Henry Blackwell had married her.
Mr Blackwell shared his wife’s commitment to reform, particularly in the area of women’s rights.
“Mr Blackwell, who was engaged in business and might have fewer hours to give to home occupations, declared himself more than willing to help me with home duties. This promise he generously more than redeemed for almost fifty years,” Antoinette wrote after her husband’s death.
They had seven children, two of whom died in infancy. Edith and Ethel, two of the remaining five daughters, went on to become doctors, while Agnes went on to become an artist and an art teacher.
Brown Blackwell gave up public speaking for the most part while raising her children.
She once wrote to Susan B. Anthony about the clothes she needed to sew for her daughters, her husband’s garments that required mending, and her house that required cleaning. “the whole winter store of coal and provisions to be taken in, a garden to be covered up from the frost, seeds to save, label and put up for spring, bulbs to store away, and shrubs to transplant. . . . This, Susan, is woman’s sphere!” she added. This depicted, the natural struggle of a woman when it came to finding a work-life balance.