Abigail Allen graduated from Alfred Academy, LeRoy Female Seminary, and Alfred University, and taught at Alfred Academy and University until her death in 1902. Believing in women's right to speak out publicly, she founded Alfred's first women's literary society (one of the earliest in the country) in 1846, when most school's forbade women's public speaking. An advocate for women's equal education when that was still controversial, she defended coeducation throughout her life. Alfred University, she said, "has no more thought of changing than parents who find in their families boys and girls, would think of organizing two households in which to train them."
A strong-minded woman, dedicated teacher, and reformer, Allen became an early suffragist, when many colleges did not even allow discussion of women's suffrage. With her husband, Jonathan Allen, (Alfred University President, 1867-1892), she pressed for social justice, a public role for women, broadening of their employment opportunities, and egalitarian gender relations. To the end of her life, she worked for suffrage and expansion of women's roles.
Painting was one of her many interests. She taught drawing and modelling for many years at Alfred University, and was described as an enthusiastic teacher, not only in art but also in natural history. She encouraged and inspired students of all ages with her own high ideals; teachers and students viewed her as a kindly friend. She was affectionately referred to as "Mother Allen" by many. Edwin H. Lewis remembered her by saying "But hers was not merely a great soul; it was sweet, gentle, saintly. She loved her race. She hated no man or woman. She was generous to a fault. She had a gift, a very genius, for friendship."