Sumner is a city in Chariton County, Missouri, United States. The population was 78 at the 2020 census. It was named in honor of U.S. Senator Charles Sumner. The area along the Grand River in the northwest corner of present-day Chariton County was first explored by two sons of Daniel Boone and Thomas Stanley prior to Missouri statehood in 1821. Stanley established a trading post some time later near what would eventually become Sumner. Other than the trading post not much existed in the area for several years, partly due to marshlands and flooding on the Grand River. The area around Sumner was originally known as Crossland, and about one mile away was the much larger village of Cunningham. However the coming of the Chicago, Burlington and Quincy Railroad to the community combined with the Wabash railroad's decision to move their depot from Cunningham to Sumner gave the latter the upper hand in growth. Sumner was laid out by Joel H. Wilkerson in June, 1882. That fall the first home was constructed in the new village by J.M. Vanes, soon followed by the Commercial Hotel. A newspaper, the Sumner Star, was established in 1890 and operated for several years. Once teeming with wildlife such as prairie chicken, turkey, duck, and deer in the 1800s, the population of such was drastically reduced by over hunting and draining of the native wetlands, notably Hog Lake in 1911. In 1937 concerned over wetland preservation in the wake of the Dust Bowl, the U.S. Congress established the Swan Lake National Wildlife Refuge just to the south of Sumner. Roads, buildings and man-made wetlands were soon created by the Civilian Conservation Corps and by 1941 eight hundred geese wintered in the area.