Mary Lillian Duke Biddle was born on November 16, 1887, in Durham, N.C., the only daughter of Benjamin Newton Duke and Sarah Pearson Angier Duke. She attended public schools in Durham and in 1907 graduated from Trinity College,later named Duke University in honor of her grandfather, Washington Duke. Mrs. Biddle developed an appreciation for the importance of philanthropy from her father, who was the guiding hand behind many of the Duke family’s charitable activities. Duke University, in particular, flourished in its early days thanks to the financial backing of her grandfather, father, and uncle James B. Duke, who were successful entrepreneurs as well as philanthropists.

She took an active part in the civic and social life of Durham until her marriage in 1915 to Anthony Joseph Drexel Biddle, Jr., after which she lived in New York City and Irvington-on-Hudson, NY. The couple had two children, daughter Mary and son Nicholas. Divorced in 1931, Mrs. Biddle and her children moved back to Durham for part of each year beginning in 1936. As she spent more time in Durham, her family and civic connections deepened. Her commitment to Duke University, her community, and North Carolina grew more meaningful.

In September 1956, she established The Mary Duke Biddle Foundation. She focused the foundation’s grantmaking in North Carolina and New York, in recognition of their significance to her and her family. She singled out three churches, in Durham, New York City, and Irvington, NY as institutions important to her. Mrs. Biddle also directed that at least one-half of the foundation’s grants be made to Duke University. Mrs. Biddle otherwise gave the foundation’s Board of Trustees broad discretion in determining how best to accomplish her objectives.