Sullivan was born on April 14, 1866, in Feeding Hills, Massachusetts. Her parents immigrated to the United States from Ireland during the Great Famine of the 1840s. At the age of five, Anne contracted an eye disease called trachoma, which severely damaged her sight. Her mother, Alice, suffered from tuberculosis and had difficulty getting around after a serious fall. She died when Anne was eight years old. Anne and her infirm younger brother, Jimmie, were sent to live at the Tewksbury Almshouse, a home for the poor.

Tewksbury Almshouse was dirty, rundown and overcrowded. Sullivan's brother Jimmie died just months after they arrived there, leaving Anne alone. While at Tewksbury, Sullivan learned about schools for the blind and became determined to get an education as a means to escape poverty. She got her chance when members from a special commission visited the home. After following the group around all day, she worked up the nerve to talk to them about sending her to a special school.

Sullivan left Tewksbury to attend the Perkins School for the Blind in 1880, and underwent surgery to help improve her limited vision. She was, tremendously bright, and she soon advanced academically. She developed close friendships with some of her teachers, including the school's director Michael Anagnos.

Anagnos helped Sullivan find a job after graduation. The Keller family had written him looking for a governess for their daughter Helen, who was blind and deaf. In March 1887, Sullivan traveled to Tuscumbia, Alabama, to work for the Keller family. Sullivan had studied the instruction methods used with Laura Bridgman, a deaf and blind student she had known at Perkins, before going to Alabama.

At only 20 years of age, Sullivan showed great maturity and ingenuity in teaching Keller. She wanted to help Keller make associations between words and physical objects, and worked hard with her rather stubborn and spoiled pupil. After isolating Keller from her family in order to better educate her, Sullivan began working to teach Keller how to communicate with the outside world. During one lesson, she finger-spelled the word "water" on one of Keller's hands as she ran water over her student's other hand. Keller finally made her first major breakthrough, connecting the concept of sign language with the objects around her.

Thanks to Sullivan's instruction, Keller learned nearly 600 words, most of her multiplication tables, and how to read Braille within a matter of months. News of Sullivan's success with Keller spread, and the Perkins school wrote a report about their progress as a team. Keller became a celebrity because of the report, meeting the likes of Thomas Edison, Alexander Graham Bell, and Mark Twain.

Despite the physical strain on her own limited sight, Sullivan helped Keller continue her studies at Radcliffe College in 1900. She spelled the contents of class lectures into Keller's hand, and spent hours conveying information from textbooks to her. As a result, Keller became the first deaf-blind person to graduate from college.

Working with Keller on an autobiography, Sullivan met John A. Macy, a Harvard University instructor. Macy helped edit the manuscript, and he fell in love with Sullivan. After refusing several marriage proposals from him, she finally accepted. The two were wed in 1905.

Sullivan, however, did not let her marriage affect her life with Keller. She and her husband lived with Keller in a Massachusetts farmhouse. The two women remained inseparable, with Sullivan traveling with Keller on numerous lecture tours. On stage, she helped relay Keller's words to the audience, as Keller had never learned to speak clearly enough to be widely understood.

According to biography.com