Schmidt was born in Middletown, New York, on September 2, 1889, and was named in honor of Dr. Valentine Mott, a friend of the Schmidt family. He was a son of Edward Mott Schmidt and, his third wife, Frances M. Schmidt, and grew up in a brownstone at 671 Park Place, near Prospect Park and Grand Army Plaza. Schmidt was a fourth-generation American of German and Irish ancestry. His great-grandfather was Dr. John William Schmidt; his grandfather, Dr. John W. Schmidt Jr., was the first visiting surgeon at St. Vincent's Hospital and helped start the New York Academy of Medicine in 1847. He attended public schools in Brooklyn. After graduating with a degree in architecture from the Pratt Institute in 1906, he took a two-year Grand Tour on which he drew many of Europe's best-known monuments.
Career
After returning from Europe, Schmidt worked as an apprentice in the New York architecture office of Carrére and Hastings for four years. There he learned not only to build using modern materials, but also to design in the classical styles favored by Beaux Arts trained architects. Founding his own practice in 1912, he took small residential jobs, remodeling townhouses in Brooklyn and Manhattan, and some commercial projects. During World War I, Schmidt served stateside in the U.S. Army as a First Lieutenant, supervising military installations at the Edgewood Arsenal in Maryland and at Hastings-on-Hudson, New York, during 1917 and 1918. During this period, he also completed a townhouse for Herbert J. Johnson and in 1917, the alteration of a townhouse at 39 East 63rd Street for Grenville T. Emmet, Schmidt's first important commission. Two years after the Emmet project's completion, Architectural Record wrote about it, bringing him professional recognition and attracting new patrons.
In the early 1920s, Schmidt was hired by wealthy socialites Anne Harriman Vanderbilt, second wife of William Kissam Vanderbilt; and Anne Morgan, daughter of banker J. Pierpont Morgan; and Elisabeth Marbury, to design their townhouses in the then-new Sutton Place neighborhood in Manhattan, which up to that point had been known as a "squalid place." For Vanderbilt, who had purchased the former home of Effingham B. Sutton, at 1 Sutton Place, Mott renovated the existing structure beyond recognition, transforming the home into a 13-room townhouse with terraced gardens that overlooked the East River. The $75,000 renovation was complemented by interiors designed by Elsie de Wolfe. While the society pages of The New York Times initially scoffed at the choice of location, and referred to the area as an "Amazon Enclave," the commissions launched Schmidt's career, and by 1929, the neighborhood had firmly transformed into a luxury enclave.
In 1926, Schmidt built a gracious brick country home for his family in Bedford, New York. It was called Pook's Hill, after a children’s book by Rudyard Kipling. The house won first prize in a 1931 competition for "A Common Brick House," published in The Architectural Forum, and was exhibited featured in the Architectural League of New York's 1932 yearbook. Schmidt sold the home in the 1950s.
