According to the results of the analysis, groups of factors were formed that influenced the emergence of social work in the United States in the late ХІХ – at the beginning of the XX century: socio-cultural, political-economic, industry. Accordingly, groups of factors were formed, which, on the one hand, became a prerequisite for the formation of the personality of Mary Ellen Richmond (1861–1928), and on the other - contributed to the formation of its principles and views on social work, the emergence of «case work» and «social diagnosis»: socio-cultural, political–economic, professional. The periodization of Mary Ellen Richmond's life and activity in a complex approach is theoretically substantiated: (the first stage is pre-professional, the second stage is professional development, the third stage is the period of professional authority. The socio-pedagogical content in the works of Mary Ellen Richmond's: works with clients and in the training of social workers was described. The levels of the client's social environment and the sequence of their involvement in resolving the crisis situation in accordance with the theory and practice of Mary Ellen Richmond are characterized. The researcher's understanding of the criteria of efficiency of work of charitable workers is described; researched and systematized the work of charitable organizations of the late XIX – early XX centuries and problems of their functioning are revealed; the influence of charitable organizations on the formation of social policy in the United States of the selected period is determined. Based on the generalization of the scientific and practical work of Mary Ellen Richmond, it is determined that the process of practical work of a social worker with a client has the following stages: analysis of the current situation; formulation of a «diagnosis» of a crisis situation; negotiating with all family members regarding their participation in resolving the current situation; development of an assistance plan; step-by-step implementation of this plan with periodic monitoring of progress. Through scientific analysis, in the theoretical and practical heritage of Mary Ellen Richmond identified a number of principles of social work, among which the main one is «taking into account the individuality of the client and his situation». It was emphasized that the implementation of the case work method as the basis of individual social work was carried out in such a way as to teach the client to solve crisis situations and take responsibility for decisions. The study identified the main groups of clients that Mary Ellen Richmond focused on, namely: families in difficult situations, widows with young children, minor children, people with disabilities, family deserters, recent migrants, unemployed, beggars. It is established that social work with different categories of clients was carried out at different levels (individual, in the family, local (in the community), local, state). The groups of indicators of efficiency of social work in Mary Ellen Richmond's legacy are offered. External – organizational (network of subjects of social work; requirements at an estimation of efficiency of work with various groups of clients; initial position in which the client is; the form of the help; system of work with the client; control according to the planned); and state (regulatory framework; political changes and social reforms; the presence or absence of cooperation between state and non-governmental organizations engaged in charity; climatic features of the region; the level of industrialization of the region). Internal – these are the indicators that depend on the client and the social worker who works with him, among them are: motivation and interest in changing the situation; personal qualities (both professional and universal); the presence of certain competencies. The analysis of primary sources revealed three main subject-functional lines on which Mary Ellen Richmond's activity was focused: a person (her formation in society and return to society), a social worker (his professionalism and role as an assistant in the formation and reintegration of personality), activities of charitable organizations (as active helpers in building relationships between the individual and society). The perspective ways of actualizing the ideas of Mary Ellen Richmond's social work in creative social work on three levels: methodological, organizational and practical are clarified.
