In 1975, on a vacation to visit his new wife’s family, Nicholas Nixon casually took a portrait of his wife and her three sisters lined up, staring directly into the camera. Nixon proposed they restage the photograph each year thereafter, resulting in one of the most groundbreaking serial portraits in the history of photography. Each photograph in this astounding grid represents the passage of one year in the sisters’ lives; together, they document both the flow of time and the unbreakable bonds of family.