The firms beginnings are traced to Pillsbury & Sutro which was founded in 1901 by Oscar Sutro of San Francisco, U.S.A. Oscar Sutro was joined by his elder brother Alfred Sutro and E.J. Pillsbury, both partners of the San Francisco firm of Pillsbury, Madison & Sutro. Because of a previous requirement that the name of a partner who ceases to be with the firm should be dropped from the firm name , its firm name has undergone many changes. Ross, Selph & Carrascoso and Bito, Lozada, Ortega & Castillo were the firm names for many years. All partners were Americans until 1936 when the first Filipino partner (Antonio T. Carrascoso, Jr.) was admitted.