G. W. & W. D. Hewitt was a prominent architectural firm in the eastern United States at the turn of the twentieth century. It was founded in Philadelphia in 1878, by brothers George Wattson Hewitt (1841–1916) and William Dempster Hewitt (1847–1924), both members of the American Institute of Architects. The firm specialized in churches, hotels and palatial residences, especially crenelated mansions such as Maybrook (1881), Druim Moir (1885–86) and Boldt Castle (1900–04). The last was built for George C. Boldt, owner of Philadelphia's Bellevue-Stratford Hotel (1902–04), G.W. & W.D. Hewitt's most well-known building.