Robert Adam Mosbacher Sr. was born March 11, 1927, in Mt. Vernon, New York. He graduated from Washington and Lee University of Virginia, where he earned his B.S. degree in 1947.

The following year, he began a long career as an independent oil and gas producer, serving as chairman of the board and chief executive officer of Houston-based Mosbacher Energy Company. He was a member of the National Petroleum Council, serving as its chairman (1984-1985), and of the Governor's Energy Council for Texas.

Mosbacher was a founding member and vice president of the American Business Conference, a board member of the Boys Clubs of America, and past president of the American Association of Petroleum Landmen.

President George H.W. Bush appointed him commerce secretary, and he served in that capacity from 1989 to 1992. Following his time in government, Mosbacher returned to Houston as chairman of Mosbacher Energy Company and the Mosbacher Power Group.