Oscar Hammerstein I came to New York in the 1860s, a Prussian runaway with $1.50 in his pocket, and found work at a cigar factory. A decade later he was publishing the nation’s leading tobacco trade journal and held dozens of patents for cigar-rolling machinery. He made a fortune and turned his efforts to theater.

He built eight of them, including four around Longacre Square-later Times Square-which became a thriving theater district. A daring impresario, he was involved at all levels, from booking to composition to stagecraft. Throughout the Gay Nineties and early 20th century, he billed the world’s top actors, prima donnas and vaudeville acts.

Then, as now, show business was speculation and high adventure, with rivalries fought in the headlines. Always a storm center, Hammerstein played a skillful chess game with both partners and performers while staging first-class shows for capacity crowds. This biography-from an unfinished manuscript by the son of one of his stage managers-recounts the heyday of his bold productions, his often turbulent relationships with associates, and the birth of Broadway.