Théodore Rousseau
In 1926, Billings sold his art collection, which included works by Jean-Charles Cazin, Jean-Baptiste-Camille Corot, John Crome, Charles-François Daubigny, Jules Dupré, Charles Jacque, Jean-François Millet, Théodore Rousseau, Constant Troyon, and Félix Ziem for $401,300. In 1928 he realized $4 million for the sale of the Johnson Building, located on Exchange Street from Broad Street to New Street. He was also part of a group of investors who built the Pierre Hotel in Manhattan, which opened in 1930.