Contrasting the stiff and formal schottisches and quadrilles of the past, variations on the Foxtrot became popular known collectively as American Ragtime dances. Although the Castles’ rise to fame was quick, it wasn’t immediate. Early in their marriage the Castles auditioned for Broadway mogul Lew Fields and were flatly dismissed. Fields told them, “Who’s going to pay to watch a man dance with his wife?”
They then traveled to Paris and gained quick notoriety for introducing the new dance forms to the French. Upon their return to New York in 1912, their success reached new heights. Soon after their debut performance, they were in high demand. By 1914 they had opened a ballroom dance school called “Castle House” where they taught high society by day, and a nightclub called “Castles by the Sea” where they performed to sell out crowds by night. Private dance lessons were in such demand that Vernon reportedly charged $1,000 an hour to his most demanding clients.
Later that year the Castles starred on Broadway in Irving Berlin’s Watch Your Step, in which they refined the basic Foxtrot, which then soared in popularity. The show went on a lengthy tour and brought the Foxtrot to the consciousness of the entire country. They held dance competitions along the way and culminated the tour at Madison Square Garden where they performed along with the winning ballroom dancers from each competition.
Ballroom dancing wouldn’t become stylized for another twenty or thirty years. This gave the Castles tremendous freedom and influence as they created styles and standards themselves. They disliked the “animal dances” that were the current trend. They considered dances such as the Turkey Trot, Grizzly Bear, and Chicken Scratch to be simplistic, coarse and “out of fashion.” Instead they developed dances that were more refined and often technically more difficult. Among other dances, they developed the "Castle Walk", "The Maxie" and a “hands-free” Tango they called “The Tango of Today.”
The Castles were trendsetters in many ways: they traveled with a black orchestra, had an openly lesbian manager, and were animal-rights advocates decades before it became a public issue. Irene was also a fashion innovator, bobbing her hair ten years before the flapper look of the 1920s became popular. They endorsed Victor Records and Victrolas, issuing records by the Castle House Orchestra, led by James Reese Europe -- a pioneering figure in Black music. They also lent their names to advertising for other merchandising products, from cigars and cosmetics to shoes and hats.
It wasn’t long before Hollywood came calling. The pair starred in a newsreel entitled Social and Theatrical Dancing and in the 1915 film Whirl of Life. They also published an instruction book called "Modern Dancing", which quickly became a best seller.
In 1939, her life with Vernon was turned into a movie, The Story of Vernon and Irene Castle, produced by RKO and starring Fred Astaire and Ginger Rogers. Irene served as a technical advisor on the film, but clashed with Ginger, who refused to cut or color her hair or to wear authentic reproductions of Castle's Lucile dresses.
For the rest of her life, Irene was a staunch animal-rights activist, ultimately founding the Illinois animal shelter "Orphans of the Storm", which is still active. Irene died January 25, 1969 (aged 75) She and Vernon are interred together in the Woodlawn Cemetery in The Bronx, New York.