While much attention has been devoted to connections in American families between husbands and wives and between parents and children, We Grew Up Together enters virtually uncharted territory by exploring the emotional relationships among siblings.

Through the letters brothers and sisters wrote to each other over the course of nearly a century (1840-1920), Annette Atkins reveals the inner workings of ten nineteenth-century families, illuminating their everyday lives and central relationships. Drawing on the insights of Alfred Adler and others, Atkins examines the varying dynamics of "warm"...