The Charity Organization Society (COS) played a significant role in the origin and development of professional social work during the late nineteenth and early twentieth centuries. It emerged in London in 1869 at a time when rapid industrialization, urbanization, and poverty had created serious social problems. Many charitable organizations were working independently, leading to duplication of services, misuse of resources, and ineffective assistance. The COS was established to coordinate charitable activities, ensure proper distribution of aid, and promote self-reliance among the poor. Its principles and methods laid the foundation for the modern profession of social work. One of the most important contributions of the COS was the introduction of a systematic and scientific approach to helping individuals and families. Instead of providing indiscriminate charity, the Society emphasized careful investigation of each applicant’s circumstances. Volunteers, known as "friendly visitors," collected detailed information about the social, economic, and personal conditions of families before deciding on the type of assistance required. This practice became the basis for the modern method of social casework. The COS stressed the importance of understanding the causes