Sister Margaret Mary Quinn, C.S.J., a Sister of St. Joseph, Brentwood, L.I.. for 75 years, died June 9. She was 95.

She entered the congregation in 1938 from Our Lady of Angels parish, Bay Ridge.

Her background in history began when she earned her bachelor’s and master’s degrees in History/Modern European History from St. John’s University, Jamaica. A doctorate in U.S. History followed along with grants in politics of Africa from Northwestern University, Evanston, Ill., and archives administration from Long Island University C.W. Post, Brookville, L.I.

As an archivist and historian she published several articles on the key founders of the Congregation of the Sisters of St. Joseph and was honored by the Catholic Daughters of the Americas with the Heritage Award in 1982.

She taught at St. Augustine, Park Slope, 1940-41; St. Mary Star of the Sea, Far Rockaway, 1942-43; Holy Cross, Flatbush, 1943-44; Visitation B.V.M., Red Hook, 1944-47; and St. Brendan Elementary School, Midwood, 1947-50.

She also taught at Bishop McDonnell H.S., Crown Heights, 1950-51; St. Angela Hall Academy H.S., Clinton Hill, 1951-60; and St. Joseph Commercial H.S., Downtown Brooklyn, 1960-62.

Her later ministries included Brentwood College, Brentwood, 1965-71; C.S.J. Director of Personnel, Brentwood, 1969-74; Suffolk Community College, Selden, L.I., 1974-78; St. Joseph College, Patchogue, L.I., and Brooklyn, 1974-83; St. Francis College, Brooklyn Heights, 1975-77; and Archivist/Historian, Brentwood, 1977-94.

In 1994, she retired to Sacred Heart Convent, Hempstead, L.I., and later moved to Maria Regina Residence.

A Mass of Christian Burial was held in Sacred Heart Chapel, Brentwood, where she had instructed many visitors about its history. Interment followed in Calvary Cemetery, Brentwood.