In 1710, Henri François d'Aguesseau, Chancellor of France, acquired a tract of land which included the present site of the Hôtel de Pontalba. Ten years later, he built a house, and the house subsequently passed through a series of owners. New Orleans-born Baroness Micaela Almonester de Pontalba purchased the property in 1836, and by 1842, she had demolished the d'Aguesseau house and commissioned the architect Louis Visconti to design a newer house for the site.[1]
Construction of the mansion was finished in 1855. Baroness de Pontalba occupied the mansion until her death in 1874, upon which it was willed to her heirs who sold the property to Baron Edmond James de Rothschild in 1876. Baron de Rothschild hired Felix Langlais to substantially renovate, enlarge, and embellish the residence, leaving only the original gatehouse and portals intact, but following much of the H-shaped ground floor plan.[1]