Part I. Background; Introduction; Part II. Early Foundations; 1. From Simmel, 'On the Significance of Numbers for Social Life: Introduction,' 'The Isolated Individual and the Dyad,' 'The Triad,' and The Web of Group Affiliations: Commentary, 'Georg Simmel's Contribution to Social Network Research'; 2. From Katz and Lazarsfeld, Personal Influence: Commentary, 'Influencers, Backfire Effects and the Power of the Periphery'; 3. From Mitchell, 'The Concept and Use of Social Networks': Commentary, 'On J. Clyde Mitchell's 'The Concept and Use of Social Networks''; 4. From Bott, 'Urban Families: Conjugal Roles and Social Networks': Commentary, 'Commentary on Bott's 'Family and Social Network''; 5. From Festinger, Schachter, and Back, Social Pressures in Informal Groups: Commentary, 'Festinger, Schachter, and Back's Social Pressures in Informal Groups'; 6. From Bernard et al., 'The Problem of Informant Accuracy': Commentary, 'Implications of Informant Accuracy Research for Ego Networks'; 7. From White, Identity and Control: Commentary, 'On Parachutes and Lion-Taming'; Part III. Later Foundations; 8. From Fischer, To Dwell among Friends: Commentary, 'From the Northern California Community Study, 1977-78, to UCNets, 2015-20'; 9. From Granovetter, 'The Strength of Weak Ties': Commentary, 'Strength of Weak Ties in the Labor Market: An Assessment of the State of Research'; 10. From Wellman and Wortley, 'Different Strokes from Different Folks': Commentary, 'A Network Pilgrim's Progress: Twenty-Six Realizations in Fifty-Five Years'; 11. From Coleman, 'Social Capital in the Creation of Human Capital': Commentary, 'Three Decades of Research into Social Capital: Achievements, Blind Spots, and Future Directions'; 12. From Pescosolido, 'Beyond Rational Choice': Commentary, 'Confronting How People Cope with Crisis: From the Social Organization Strategy Framework to the Network Episode Model to the Network Embedded Symbiome'; 13. From Feld, 'The Focused Organization of Social Ties': Commentary, 'Reflections On 'The Focused Organization of Social Ties' and Its Implications for Bonding and Bridging' 14. From Burt, Structural Holes: Commentary, 'Structural Holes Capstone, Cautions, and Enthusiasms'; 15. From Laumann, Marsden, and Prensky, 'The Boundary Specification Problem in Network Analysis': Commentary, 'On the Boundary Specification Problem in Network Analysis: An Update and Extension to Personal Social Networks'; 16. From McPherson, Smith-Lovin, and Cook, 'Birds of a Feather': Commentary, 'The Enormous Flock of Homophily Researchers: Assessing and Promoting a Research Agenda'; 17. From Huckfeldt and Sprague, 'Networks in Context': Commentary, 'Individuals, Groups, and Networks: Implications for the Study and Practice of Democratic Politics'; 18. From Nan Lin, 'Building a Network Theory of Social Capital' Commentary, 'Social Capital: An Update'; 19. On the General Social Survey: 'Egocentric Network Studies within the General Social Survey: Measurement Methods, Substantive Findings, and Methodological Research'; Part IV. New Perspectives; 20. On Cognition: 'Network Representation Capacity: How Social Relationships are Represented in Human Mind'; 21. On Mobilization: 'How Actors Mobilize their Networks in Practice'; 22. On Trust: 'Self-Verification, Trust, and Social Capital Mobilization'; 23. On Dynamics: 'Personal Network Dynamics: Organizing Principles of Stability and Change from Complex Systems Theory'; 24. On Inequality: 'The Context of Network Inequality'; 25. On Culture: 'The Problem of Culture Flows in Weak Ties'; 26. On Migration: 'Personal Networks and Migration Trajectories'; 27. On Movements: 'The Opportunities and Challenges of Studying Social Movement Ego-Networks: Online and Offline'; 28. On Social Media: 'Studying Social Media from an Ego-Centric Perspective'.