William Andrew McCampbell III, 60, a lawyer who worked on private-sector development in Iraq and Afghanistan and who ran for a California congressional seat in the 1990s, died of brain cancer Sept. 21 at George Washington University Hospital.

As a lawyer for more than 30 years, Mr. McCampbell helped set up nearly 3,000 business ventures in the United States and around the world. In 2004, the Bush administration, recognizing his background and expertise with business start-ups, asked him to help create a viable business environment for Iraq as the deputy adviser for economic reform for the Coalition Provisional Authority.

The Iraq experience was frustrating, his wife noted, but he had more success in Afghanistan, where he worked as diplomatic attache and senior adviser for private-sector development. Attached to the U.S. Embassy in Kabul, he helped and encouraged the Afghan people to establish businesses. As his wife remarked, he understood the complexity and challenge of attracting donors and investors to support business start-ups in the midst of conflict, yet he was determined to succeed. He stayed in Afghanistan until the onset of his illness in December.

A fifth-generation Californian, Bill McCampbell was born in Sacramento and was co-captain and quarterback of his high school's championship football team as well as class president. He graduated from the University of California at Davis in 1967 and was selected for an honors program that allowed him to study for a year at the University of Gottingen, Germany. He met the woman he would marry on the plane to Paris.

He graduated from the University of California at Davis Law School in 1970 and lived in France for a short period before joining the Babcock & Wilcox Co. in Lynchburg, Va., where he worked on forming international ventures in the nuclear power industry, structuring agreements in Sweden, Italy, Spain and Germany. He moved to Washington in 1972.

He was eager to work for himself, so in 1975 he started his own District law practice with money he borrowed on his credit card. Within a short time, he began to focus his practice on what would become his life's work: helping people establish businesses.

Through his work on international transactions, he also got involved in business development in numerous struggling countries, including the Transkei region of South Africa and Tajikistan. He believed that small business was the driving force of economic freedom.

In 1985, he moved to Pebble Beach, Calif., maintaining his D.C. law practice by telecommuting. In the 1990s, he ran for Congress four times in California's 17th District, a district that had been in Democratic hands since 1976.

He never won, although he came close in 1994, running as an environmentalist Republican who backed abortion rights and refused campaign money from political action committees. In the 1998 race, he proposed radical tax reform that would eliminate the Internal Revenue Service and replace it with a single-tax system. The Democratic incumbent, Sam Farr, won handily.

Mr. McCampbell returned to the practice of law, moved back to Washington and resumed his work with people who wanted to start businesses. Toward the end of his life, his wife said, he was ruminating about running for Congress again -- perhaps from Northern Virginia, perhaps as a Democrat.

He served as a board member and treasurer of Watergate South and was a member of the D.C. Bar and the U.S. District Court for the District of Columbia.

Survivors include his wife of 38 years, Jamie McCampbell of Washington; a son, Drew McCampbell of Ashland, Ore.; his mother, Ruth McCampbell of Chico, Calif.; a sister, Margaret Gifford of Baltimore; and two brothers, Frank McCampbell of Willows, Calif., and Tom McCampbell of Sacramento.

William A. McCampbell III advised the provisional government in Iraq on economic reform.