Named by the Hon. L. F. Thompson, for Sen. Charles Sumner, when the first post office was established in 1876. Other versions of the name origin exist. It was one of the first settled areas in Pierce County and until around 1941 was focused on agriculture and then redeveloped into a modern community taking advantage of improvements to transportation. Known as the Rhubarb Pie Capital of the World, Sumner remains a largely agricultural community. Its historic downtown is home to a variety of shops and businesses and the center of many community events including the Daffodil Parade, Wine Walks and Music Off Main. Although the north side of town remains industrial, east Main Street hosts a lively business district with plenty of restaurants, shopping and services.

Sprawled among the trees on the banks of the Stuck River, which links the White and Puyallup Rivers, is Sumner an industrial and trading center for the Puyallup Valley. A clean and bustling community, it was noted for its berries, vegetables, rhubarb, and flower bulbs. Some of the streets leading from the business district once terminated in berry fields and produce gardens. Warehouses and canneries once lined the bank of the river, and there were two large floral supply houses and two dairy plants.

Sumner was headquarters of the Washington Berry Growers, The Puget Sound Vegetable Growers, the Sumner Rhubarb Growers, Washington Packers, the Puget Sound Bulb Exchange, the Rhubarb Growers’ Association, and other such associations. By the 1940s, the district shipped 150 carloads of rhubarb annually. The United States Department of Agriculture also maintained an Entomological Research Laboratory here.