Seen in her camera’s viewfinder, LaToya Ruby Frazier takes a self-portrait at the site where a bridge named after her family once stood in Braddock, Pa. on April 8, 2024. Frazier, perhaps America’s foremost social documentary photographer, features her hometown at length in a new survey exhibition, “Monuments of Solidarity,” at the Museum of Modern Art. (Gioncarlo Valentine/The New York Times)