Educated in the Wilmington public schools, Stewart studied civil engineering at the University of Delaware and left in 1911 during his junior year. (He received an honorary B. S. from the university in 1958. )
Stewart's father had founded a heavy construction company, Stewart and Donohue, in 1902, and Stewart joined it in 1911, working in a variety of capacities and rising to partner in 1919 and president in 1929. The firm became one of the largest in the Middle Atlantic region and built highways, bridges, factories, and residences.
Stewart developed close ties with both local politicians and the du Pont family. Under his supervision, the firm restored the original du Pont black powder plant at Hagley, Delaware, and constructed the museum house for Henry F. du Pont at Winterthur, Delaware, and the extensive classical garden extensions for the Alfred I du Pont estate, Nemours, near Wilmington, Delaware.
During this period, Stewart came into contact with leading architects from Philadelphia and New York City, and his architectural tastes were formulated in the classical and traditional styles, not in modernism. The political stage of Stewart's life began in 1931 with his appointment for a year as a member of the Governor of Delaware's Emergency Relief Commission.
After he was defeated for reelection in 1937, he returned to his construction business, which he sold in 1942. During the war he worked for the Hercules Powder Company of Wilmington as a salesman to the United States Army Corps of Engineers. After the war he worked as a salesman for the Pennsylvania Engineering Company. In 1947 he returned to Washington, D. C. , as chief clerk of the Senate Committee on the District of Columbia. He continued as a professional staff member under the Democratic majority during 1949-1951.
In recognition of these services, President Dwight D. Eisenhower named Stewart architect of the Capitol on October 1, 1954. The eighth person to occupy the position of architect of the Capitol since it was created in 1793, Stewart was in charge of the operation, maintenance, and construction of all buildings and grounds in the Capitol Hill compound of approximately 131 acres. The architect of the Capitol is immune to all local building laws, zoning, and planning commissions, especially the Commission of Fine Arts, which oversees Washington's architecture. (Although appointed by the president, the architect in effect serves at the pleasure of the leaders of Congress. )
Beginning in 1963, Stewart advanced ideas for the extension of the west front of the Capitol. This extension, which would have removed the last external vestige of the original Capitol building, was controversial. Stewart's reign on Capitol Hill was controversial, and the criticism of him frequently vituperative.
Writers in the professional architectural press and critics for newspapers and magazines bemoaned his impact. He was called "the Emperor of Capitol Hill" and "the Monster Builder, " and his work was labeled "Mussolini modern, " "Early Rameses and Late Nieman-Marcus, " "King-Sized Howard Johnson's, " "Texas Penitentiary, " and "hard, grotesque, vulgar. "
The American Institute of Architects issued several formal criticisms of his Capitol Hill work and projects. Stewart, a short round man with a courtly demeanor, appeared unmoved by the various attacks and would simply reply, "No comment. " Close friends, however, reported that the criticisms did sting.
While roasted in the press, Stewart found only a few congressional critics; most were either pleased with his performance or simply oblivious to the charges of philistinism. Senator Everett Dirksen labeled Stewart's critics "that aesthetic group" and claimed Congress would not be told by anybody what to build or how to build it.
Stewart's secret was to please Congress by offering members office space and facilities such as swimming pools and to appeal to the edifice complex of the leaders of both the Senate and the House. Although a Republican, he got on well with Democrats and found his strongest supporters among their ranks. Speaker of the House Sam Rayburn viewed the extension of the east front of the Capitol as a personal memorial and, together with the Senate majority leader, Lyndon Baines Johnson, pushed it through. To critics, it was known as "the Texas front. "
The House (Rayburn) Office Building was entirely Rayburn's creation, since he arranged for Congress to fund the project, the cost of which rose from $50 million to nearly $150 million. Rayburn convinced President John F. Kennedy to keep Stewart on the job in 1961 after Kennedy had vowed to fire him. Rayburn's successor as Speaker, John McCormack, saw Stewart as a barometer of his political power and viewed the west-front extension as a personal memorial.
The controversy around Stewart's work, especially among professional architects, must be viewed from a historical perspective. Stewart represented the old order, his architectural aesthetics were classical and traditional.
With minor exceptions, all American governmental buildings were classically derived; Stewart saw it as his duty to continue this image.
However, by the 1950's many American architects, the architectural press, and the architectural schools had converted to modernism. Modern architecture, with its abstract, ahistorical posture, was seen as the wave of the future.
Some of the design work done under Stewart has a banal touch; fineness of detail is lost and broad, blank, immense Georgia-marble surfaces dominate. In the Rayburn Building, grand staircases lead nowhere and massive muscular Valkyries gaze down on the passerby. Yet Stewart's buildings did continue the classical tradition in Washington.
He died on May 24, 1970 in Washington District of Columbia.
He was a member of the Republican Party, who served as United States Representative from Delaware and as Architect of the Capitol. In 1934 he was elected on the Republican ticket as a representative to the Seventy-fifth Congress. He remained active in Republican politics during the elections of 1944, 1948, and 1952, and he served as director of the Republican Speakers' Bureau for 1953-1954.
Sensitive to the charge that he was not an architect, Stewart would proudly point to the honorary membership the American Institute of Architects gave him in 1957.
He married Helen Tabor Ferry of Norristown, Pennsylvania, on October 7, 1911; they had two children. Stewart's wife died in 1936, and in October 1937 he married Rae (Dickerson) Lauritsen. His second marriage was unsuccessful, and so the couple separated.