M. Annie Leitch was born in Ontario, Canada to Alexander Leitch and Annie McEachern of Scotland. She developed an early interest in health due to family illnesses and death, including the loss of her mother when Annie was five years old. She began teaching at age 17 and planned to specialize in history or English, but changed her field when the topic of hygiene was introduced. World War I piqued her interest in becoming a nurse and she promptly entered Winnipeg General Hospital School of Nursing in 1917. Her studies were interrupted due to illness, but she completed the program in 1924.

After two years work at a clinic upon graduation, she began work at Butterworth Hospital, but soon left to become Assistant Director at Jackson Hospital. In subsequent years she worked as an instructor at Women's Hospital in Detroit and Grace Hospital and then as Educational Director at University Hospital in Ann Arbor. During this time she also completed her Masters Degree in Nursing School Administration.

In August 1936, M. Annie Leitch returned to Butterworth Hospital to be Director of Nursing and the School of Nursing. Upon accepting her duties, she found the nursing program in a great state of confusion, as were most programs at that time. While there she established classrooms, improved the library, attended and sent other personnel to professional conferences, developed a recreation program for student nurses, fought against anti-nursing biases and instituted an eight-hour work day for nurses. Her most admirable accomplishments involved World War II, during which she worked under desperate conditions to maintain an able nursing staff while her student nurses were serving overseas in growing numbers. She kept contact through correspondence with the enlisted nurses and provided them a much-needed feeling of closeness to home. Leitch also served as president of state and district nursing associations and was a member of the Michigan State Board of Registered Nurses. She retired from Butterworth Hospital in 1952.

Butterworth Hospital is a non-profit corporation, organized in 1873. On February 11, 1873, the first recorded meeting of St. Marks Church Home, from which Butterworth Hospital developed, was held on the west side of what is now Bond Avenue, just south of Crescent Street. In 1876 articles of association were executed incorporating the church home under the name of St. Marks Home and Hospital. The construction of the new St. Marks Hospital began in 1888 after a sizable donation by Richard Butterworth. In 1894 the name was changed to Butterworth Hospital, and all connection with St. Marks Church was dissolved in 1902. A new building was erected in 1925 and the hospital has undergone many structural changes and improvements since that time.