Mary Jackson Loftus Craighill, 78, a pioneer in the field of sacred dance who was the daughter of U.S. Supreme Court Justice Robert H. Jackson, died June 4 at Collington Episcopal Life Care Community in Mitchellville of complications from cancer.

Her St. Mark's Dance Company toured nationally and internationally with her modern dance choreography, both liturgical and secular.

Born and reared in Jamestown, N.Y., she came with her family to Washington in 1933, when her father began his government career.

She graduated in 1938 from National Cathedral School and in 1942 from Smith College, where she majored in psychology -- taking several classes in which she and Betty Friedan, who became a prominent feminist, were the only students. The two remained friends.

Mrs. Craighill later studied dance at Connecticut College. She began her own dance school and dance company in 1952.

Beginning in 1957, Mrs. Craighill provided choreography for John Langstaff's holiday season "Revels" for 30 years.

She founded the St. Mark's Dance School and Company in 1962. The company performed regularly at its home base, St. Mark's Episcopal Church on Capitol Hill in Washington. The company also conducted dance workshops in public schools in District of Columbia and Northern Virginia during the 1960s and 1970s. Mrs. Craighill was the director of the Arlington County dance program from 1969 until 1974, and in 1971, she created the Arlington Dance Theatre, a professional, resident company.

Returning full-time to St. Mark's in 1975, she began to change the company's emphasis to outreach -- to the immediate community with Lunch Theaters at St. Mark's Church and to the wider community with performances at hospitals and charitable group residences, including the House of Ruth and the Washington Home.

The company also performed at the Kennedy Center, Wolf Trap and the Washington National Cathedral, and it toured Russia in 1990 and the Czech Republic in 1995 under the auspices of the Friendship Ambassadors Foundation. Mrs. Craighill retired as director of the St. Mark's Dance School and Company last year. Mrs. Craighill developed an interest in religious dance as a means to heighten religious expression. Among her recent works of choreography is "Prayer," a dance to lyrics written by a victim of the Chernobyl nuclear disaster whom she met in Russia during the 1990 tour.

Her work has been profiled in Time Magazine, Dance Magazine and Dance Teacher Now, among other publications. The Metropolitan Dance Association of Washington honored her with a special award in 1980 for her pioneering efforts in dance.

Her marriage to Dr. Thomas A. Loftus ended in divorce.

Survivors include her husband of 47 years, G. Bowdoin Craighill Jr., of Mitchellville; two sons from her first marriage, Thomas A. Loftus of Vienna and Robert H.J. Loftus of Great Falls; a daughter from her second marriage, Julia E. Craighill of Chevy Chase; a brother, William E. Jackson of New York City; and five grandchildren.