Mielatz immigrated with his parents to America in about 1870. He studied drawing at the Art Institute of Chicago; and with Frederick Rondel; and worked in Newport for a time before settling permanently in New York in the mid 1880s. He was a moving force in the revival of etching in America in the last decades of the 19th century and served as secretary of the New York Etching Club for a number of years. Manhattan was often the subject of his work. He taught etching at the National Academy school for many years beginning in 1900. He served on the jury for the art section of the Louisiana Purchase Exposition in St. Louis in 1904. At his death, his widow gave the Academy many of his etching tools and equipment for the use of students in the Academy school.
