Nesselroth was active as an architectural draftsman and designer in the early 1910s. He worked as a draftsman for Slee and Bryson, Architects of Brooklyn, New York and was a member of the Boston Architectural Club. He and Ernest Hayward of Boston submitted a design for a suburban house and garage to be built of "Natco XXX" hollow clay tile, which won an honorable mention in a contest sponsored by the manufacturer in 1915. He also won a $50 prize at Harvard for his "design for a clock suspended or supported on an extension wall over a jeweler's shop".
Nesselroth earned his architecture degree from Harvard University in 1916. In 1922 he collaborated with Charles Paff & Company of New York on an entry in the international competition for the Tribune Tower in Chicago, Illinois.
Nesselroth was later employed by Wood-Hulse-Yates Company, Engineers in New York. Eugene Yates, who had been chief engineer for the Alabama Power Company in 1912–14, returned as General Manager. It was at his insistence that Nesselroth be consulted as an in-house architect on possible designs for a centralized office building in Birmingham.
When the utility contracted with Warren, Knight and Davis to serve as design architects for what became the 1925 Alabama Power Building, they asked the firm to employ Nesselroth and to credit him as an associate. In an interview with society-page columnist "Dolly Dalrymple", he claimed credit for designing a Presbyterian church in Tampa, Florida; a high school in Gainesville, Georgia; and a courthouse in Cross Hill, South Carolina. Architectural historian John Schnorrenberg has tried, in vain, to verify those claims.
Shortly after completion of that project, Nesselroth opened his own office in the Farley Building. That practice peaked with the design for the massive Hassinger Castle on Carlisle Road, completed in 1929. He designed a stone house for William E. Mitchell of Atlanta, Georgia in 1929.
Nesselroth was also involved in business. He, his wife, Mildred and Sol Catonzano incorporated the Doll House Sweet Shoppe in October 1926. In 1927 he was secretary of the American Business Club in Birmingham.
In the 1930s Nesselroth moved to Hollywood, California and took a job as a matte painter with the art department at Metro-Goldwyn-Mayer studios. He was one of the numerous artists in the department contributing to such visually groundbreaking films as The Thief of Bagdad and The Wizard of Oz. His wife, Mildred, was arrested in Los Angeles during the 1945 film strike.
Later in life Nesselroth returned to the practice of architecture.
- "Nesselroth won architect's prize." (March 8, 1916) The Harvard Crimson
- Dalrymple, Dolly (January 8, 1928) "Dolly Finds Skyscrapers an Opportunity to Study Art in Color." The Birmingham Age-Herald
- Schnorrenberg, John M. (1999) Remembered Past, Discovered Future: The Alabama Architecture of Warren Knight & Davis, 1906-1961. Birmingham: Birmingham Museum of Art. ISBN 0931394430
- Adams, Cathy Criss (2002) Worthy of Remembrance: A History of Redmont. Birmingham: Redmont Park Historic District Foundation/EBSCO Media ISBN 0971784000