The commercial center of the popular music publishing industry changed during the course of the 19th century, starting in Boston and moving to Philadelphia, Chicago and Cincinnati before settling in New York City under the influence of new and vigorous publishers which concentrated on vocal music. The two most enterprising New York publishers were Willis Woodard and T.B. Harms, the first companies to specialize in popular songs rather than hymns or classical music. Naturally, these firms were located in the entertainment district, which, at the time, was centered on Union Square. Witmark was the first publishing house to move to West 28th Street as the entertainment district gradually shifted uptown, and by the late 1890s most publishers had followed their lead.