The Duke name is often associated with the tobacco business. After serving in the Civil War, Washington Duke returned to his North Carolina farm, now the Duke Homestead in Durham, and began growing tobacco. His firm — W. Duke, Sons, and Company — became a major producer of tobacco goods. Being smart entrepreneurs, the Dukes branched out into other businesses such as textiles and hydroelectric power.

James Buchanan Duke was the most financially successful member of the family. He made two fortunes — the first in tobacco and the second in hydroelectric power. In 1904, he and his associates founded what has become the Duke Power Company. Now a part of Duke Energy, the power company provides electricity to families and businesses in North and South Carolina. Part of the money the company makes is given back to the people of the Carolinas through The Duke Endowment, the charitable trust that James B. Duke created in 1924.

The Duke Endowment is distinct from Duke University and is not Duke University's endowment. The Duke Endowment's office is in Charlotte, North Carolina. Since 1925, it has given more than a billion dollars to the people of North and South Carolina. The Duke Endowment makes gifts to support child care, churches, higher education and hospitals in the Carolinas. Duke University, named for the family, is one of four schools that receive funds from the Duke Endowment. The others are Johnson C. Smith UniversityDavidson College, and Furman University.

In establishing The Duke Endowment, James B. Duke was following a family tradition of giving back to the community. His father, Washington Duke, supported educational and religious causes. His older brother, Benjamin Newton Duke, managed the family's charitable interests for years. Doris Duke, James B. Duke's only child, continued the tradition by setting up the Doris Duke Charitable Foundation. The foundation supports the arts, child care, the environment and medical research. Another family philanthropy is Durham's Mary Duke Biddle Foundation, established by Benjamin N. Duke's daughter, Mary Duke Biddle.