Pratt was a native of the Clinton Hill neighborhood of Brooklyn. His mansion at 213 Clinton Avenue was constructed in 1908, but, in 1914, the Pratt's moved to 640 Park Avenue in Manhattan, a luxury building designed by J. E. R. Carpenter. In 1916, the 12-story 907 Fifth Avenue building, also designed by Carpenter, was completed, and Pratt, then vice president of Standard Oil, rented the largest apartment, 25 rooms and eight baths, occupying the entire top floor, at an annual rent of $30,000. It was the first building developed to replace one of the mansions previously fronting on Central Park.