A railway hopper car end structure and method of assembly is disclosed. The end structure includes a bolster assembly having a bottom plate extending transversely between the side sills and an upper arcuate wrap sheet secured at the opposite side sheets and at the inclined slope sheet. Diagonal gusset plates and vertical web plates extend between the wrap and bottom sheets to strengthen the bolster assembly. The bolster assembly carries a conventional center sill and center plate assembly. A plurality of generally semi-circular diaphragm plates extend transversely between the wrap sheet and the slope sheet at locations above the car axis and center plate to structurally stiffen the car body. The method of assembly consists of forming a sub-assembly including the bolster assembly, slope sheet and diaphragm plates and joining the sub-assembly to another sub-assembly including the side sills and intermediate bulkheads to permit alignment of the car during fabrication. The top and side sheets are then joined to one another and to the side sill and end structures to enclose the hopper car.