HAMMERSTEIN, Oscar (1847?-1919), German-American opera impresario, a prominent figure in the history of U.S. opera. Born in Stettin (now Szczecin, Poland), at the age of 16 he went to New York City,
where he worked in a cigar factory. He made a fortune from a cigar-making machine and other inventions and from real estate investments. He wrote and composed the music for a number of plays and built several theaters.
In 1906 he built the second Manhattan Opera House, a serious rival to the Metropolitan Opera House, which purchased it in 1910.