None of the Broadway plays mentioned in the movie were performed by Mrs. Leslie Carter. Her Broadway debut was in a play called "The Ugly Duckling" in 1890, not "The Way of Beauty." Her second play was "Zaza," not "The Lady From France." It is not known why the names of her plays were changed.
The opening scene shows citizens of Chicago on the steps of City Hall dressed for Spring, with some ladies fanning their faces as if it was uncomfortably hot. In reality, on the May date being depicted, temperatures were abnormally cool. There was light snow a couple days later, and the high temperature on Memorial Day that year was only 42.
When Caroline goes to ascend the stairs at the Lyceum Theatre to meet Belasco the first time, a clear shadow of the boom microphone moves on and off the wall behind her.
Although the boarding-house tenants are so poor they're even behind on their rent, they all show up on opening night in top hats, white ties and tails.