George M. White poses with a model of the U.S. Capitol in 1976. (Gerald Martineau/THE WASHINGTON POST)

George M. White, who spent almost 25 years as architect of the Capitol, the official charged with maintaining the structural and historical integrity of the U.S. Capitol, Supreme Court, Library of Congress and surrounding grounds, died June 17 at his home in Bethesda. He was 90 and had Parkinson’s disease.

Mr. White, named to the position in 1971 by President Richard M. Nixon, was the first practicing architect in more than a century to have the Capitol’s top architectural job. He was also trained in electrical engineering, business management and law — a background that proved useful in sometimes delicate dealings with the congressmen he called his “535 bosses.”

Soon after Mr. White came to work, he entered a cluttered room used for storage. He learned that it was the original chamber of the Supreme Court — which had met in the Capitol until 1935 — and had it restored and opened to the public. From then on, he had to balance the conflicting demands of preservation, expansion and modernization.

More than most, Mr. White saw the Capitol and its surrounding buildings as a working office complex, with modern-day needs for parking, air conditioning and electrical wires. He also recognized the role of the Capitol as a landmark and symbol of American ideals.

“People become very emotional about it,” he told The Washington Post in 1977. “And that’s understandable. After all, this building is symbolic. It’s the temple of freedom known all over the world, the heart of democracy.”

As architect of the Capitol, Mr. White had a staff of 2,300 and an annual budget that topped $170 million during his tenure. In addition to the Capitol, its office buildings and grounds, he was responsible for maintaining the Supreme Court, Library of Congress, U.S. Botanic Garden and a federal judicial building near Union Station.

Mr. White oversaw construction of the Hart Senate Office Building, the Library of Congress’s James Madison Building and the Thurgood Marshall Federal Judiciary Building.

He made subtle innovations that affected how the Capitol is seen and used. He recommended that presidential inaugurations be moved from the east side of the building to the more majestic western facade, overlooking the Washington Monument and the Mall. Since Ronald Reagan took office in 1981, all inaugural ceremonies have occurred on the Capitol’s west front.

A onetime professor who invariably wore a bow tie, Mr. White sometimes got his hands dirty. In 1993, he clambered to the top of the Capitol dome to help with the restoration of the Freedom statue. The deteriorating 19-foot bronze was lifted from its perch by helicopter, painstakingly refurbished, then hoisted back in place.

Mr. White also supervised the improvement of the electrical and transportation systems in congressional office buildings, renovated the old Supreme Court and Senate chambers and restored the rotunda, inside and out.

In 1994, Sen. Daniel Patrick Moynihan (D-N.Y.) said, “He has been our finest architect since William Thornton” — who designed the Capitol building in the 1790s.

George Malcolm White was born Nov. 1, 1920, in Cleveland and had a broad range of interests throughout his life.

At the Massachusetts Institute of Technology, where he received simultaneous bachelor’s and master’s degrees in electrical engineering in 1942, he participated in rowing, fencing and pistol shooting. He was also a competitive sailor and figure skater and an amateur hockey referee.

During World War II, Mr. White was an engineer for General Electric, helping to build radar systems.

After receiving a master’s degree in business administration from Harvard in 1948, he returned to Cleveland to join his father’s small architecture practice. He graduated in 1960 from law school at Cleveland’s Case Western Reserve University, where he also taught architecture.

He was a national vice president of the American Institute of Architects when the architect of the Capitol died in 1970, and several Ohio congressmen recommended him for the job. His three predecessors had no training in architecture.

Mr. White introduced a new professionalism and understanding of architectural and urban history. He made preservation a priority and served on planning commissions for the District and the redevelopment of Pennsylvania Avenue. He was a member of committees to restore the Statue of Liberty and to preserve Egyptian monuments in the Nile valley.

In 1994, a General Accounting Office report found that Mr. White’s office had no affirmative action program and that women and minorities were underrepresented in upper management. Several members of Congress called for him to resign.

Mr. White apologized and submitted plans to make his office conform with federal hiring and promotion standards. He retired in 1995.

He was the last architect of the Capitol with a presidential appointment. New rules were passed in 1989 requiring the Capitol architect to receive Senate approval for a 10-year term.

Mr. White’s marriage to Louise Gaus White ended in divorce.

Survivors include his wife of 38 years, Susanne Neiley White of Bethesda; four children from his first marriage, Stephanie White Bradford of West Stockbridge, Mass., Geoffrey G. White of Guilford, Conn., and Jocelyn White and Pamela G. White, both of Washington; three stepchildren, Stephen H. Daniels of Chagrin Falls, Ohio, Michael S. Daniels of Potomac and Cynthia E. Daniels of Valencia, Calif.; and eight grandchildren.

Mr. White stayed out of politics during his 24 years as architect of the Capitol and said the job gave him a deep appreciation of the history and institutions at the heart of the nation’s government.

“We want to preserve our past so we can tell where we came from,” he told The Post in 1977, “so that maybe that will put us in the direction of where we want to go.”