Modernism in its high form was like a religion in that it was Manichean -- having defined sets of things that are either good or evil. Among the "good" things so far as architecture was concerned were that form should follow function and that there ought to be truth to materials. What was "evil" was creating designs based on historical styles, thereby ignoring pure function and mis-using new materials (among other things), an act of dishonesty.
Like the painters I discussed in my book, some architects were Modernist pioneers who by some point before 1950 had run out of new Modernist ideas. These were largely Europeans of the Bauhaus mode. Then there were practicing architects in Europe and, perhaps especially in America, who were trying to figure out what to do about that Modernism thing. Cherrypick an idea or two for application on a traditional base? In some respects, that was what Art Deco was. Or going whole-hog modernist, which is what George Howe (1886–1955) did.
Some background on Howe can be found here and here. In brief, Howe, a Harvard man, was classically trained at Paris' École des Beaux-Arts, graduating in 1912. He began his practice in the Philadelphia firm of Furness, Evan & Co., and in 1916 joined the firm headed by Walter Mellor and Arthur Ingersoll Meigs. By the early 1920s after having served in the Great War he was now a partner in Mellor, Meigs and Howe. The firm specialized in residential architecture using Norman and Tudor styles. Then in 1928 Howe left the firm, proclaiming his conversion to Modernism. He started his own firm, taking on the young Swiss modernist Architect William Lescaze as a partner. Their major commission was Philadelphia's landmark Philadelphia Savings Fund Society Building, one of the first and best modernist American skyscrapers. Thereafter, as best I can tell, Howe himself designed few if any noteworthy buildings.
But before he went Modernist, Howe was a thoroughgoing traditionalist architect. Examples of his work are shown below.