Many of his most characteristic projects were for commercial buildings where new requirements pushed the traditional boundaries of design. Many of the buildings he designed have been demolished, since their central locations in New York and other cities made them vulnerable to rebuilding in the twentieth century. Some of his lost buildings were regarded as landmarks of their era. He was active from 1869 almost until his death in 1913. His sons, who had been taken into the firm in 1904, continued as George B. Post and Sons through 1930.