Matilda Electa Joslyn was born March 24, 1826, at the Cicero, New York, home of Dr. Hezekiah Joslyn and his wife, Helen. She grew up in an unusually comfortable home by the standards of that time and place—and in an abolitionist home that was an active station on the Underground Railroad. Moreover, her father raised her in a novel way, teaching her physiology and anatomy, among other subjects. Even as a young girl, she would ride alongside him on his medical rounds to outlying communities.
There are interesting parallels between Matilda's upbringing and that of Mary Edwards Walker. Each had fathers who provided their daughters with the sort of education usually provided only to boys. After completing her public education, Matilda attended the Clinton Liberal Institute, a progressive school.
When Matilda was older, her father tried unsuccessfully to secure her admission to a medical school. She later wrote of Hezekiah Joslyn’s tutelage: “If there has been one education of more value to me than all others, it was the training I received from my father to think for myself. ... This one early lesson of examining all questions for myself has been of infinitely more value to me than all the classics and sciences of the world would have been without free thought.”
Matilda Joslyn married the abolition activist Henry Hill Gage on January 6, 1845, aged eighteen. The couple would have five children, four of whom lived to adulthood.