Susan Meiselas, who joined Magnum Photos in 1976, is also the president and co-founder of the Magnum Foundation. Born in 1948 and starting as a teacher in the South Bronx, she went on to produce a definitive chronicle of Nicaragua’s Sandinista revolution. More recently, she has led the foundation’s efforts to nurture a new, diverse generation of photographers. Her books include “Carnival Strippers,” “Nicaragua,” and “Prince Street Girls.” In the last year, she has also been the subject of two books, “Susan Meiselas: Mediations” (Damiani) and “Susan Meiselas: On the Frontline” (Thames & Hudson). She spoke with James Estrin about her career. The conversation has been edited for clarity and length.