We show that the structural change of the economy from agriculture to industry was a major determinant of the observed shift in intergenerational coresidence. We build a one-good, two-sector overlapping generation model of the structural change out of agriculture, in which the coresidence choice is endogenous. We calibrate the model on U.S. data and simulate it. The model can match the decline in U.S. intergenerational coresidence both qualitatively and quantitatively.