Brandt was educated in Hamburg and Copenhagen, and apparently determined to pursue his career in America for he was twenty-one in 1852 when he arrived and settled in New York. His work made its first appearance in an Academy annual in 1855, but was not seen there again until 1860. By 1862, his third appearance at the Academy, he had moved into the Tenth Street Studio Building where he remained until moving to a secluded studio in Hastings-on-Hudson, a little north of the city, in 1865. He continued to show regularly at the Academy through 1874; during this period his work appeared in the Artist's Fund Society exhibition, 1862; the Metropolitan Sanitary Fair, and the Utica (New York) Mechanics Association, 1864; and Chicago's Northwestern Fair, 1865; and also in 1865 he had a single painting on view in the Pennsylvania Academy of the Fine Arts exhibition.
While primarily a portraitist and miniaturist, Brandt produced still lifes, landscapes, genre, and historical subjects in a variety of media. His career does not seem ever to have faltered, and although his public exhibition activity was limited, the works shown were often lent by their owners, which suggests Brandt enjoyed a steady, if uncelebrated patronage.
In 1882, after a six-year hiatus, Brandt again contributed to an Academy annual exhibition, which may not be unrelated to the fact that at the Academy's annual meeting held shortly after the opening of the exhibition, he was elected to the Council. He was reelected the following year, and also exhibited in the annual. That he only rarely exhibited thereafter, 1895, 1899 and 1902, is not surprising.
In August 1883, Brandt was named director of the newly established Telfair Academy of Arts and Sciences in Savannah, Georgia. The Telfair Academy, as was customary, was to have a collection as well as a function as an art school. Brandt made several trips to Europe to acquire works of art for Telfair, and assembled a collection of casts and photographs of major monuments in art for its school. The school, of which he was also superintendent, offered instruction in drawing, modelling, painting, and decorative arts during the winter months. Brandt maintained his Hastings studio and his work as a painter, and served as director of the Telfair Academy throughout his life. His description of himself in a letter of October 23, 1904, as having "indomitable German energy" seems somewhat understated.
