Marion Township is a township in Washington County, Iowa, United States.[1] History Marion Township was laid off in 1844.[2] References [1]U.S. Geological Survey Geographic Names Information System: Marion Township, Washington County, Iowa [2]The History of Washington County, Iowa: Its Cities, Towns, Etc. Union Historical Company. 1880. pp. 350. 41.2014°N 91.6708°W / 41.2014; -91.6708 This article about the geography of Washington County, Iowa is a stub. You can help Wikipedia by expanding it.vteWikiwand - on Seamless Wikipedia browsing. On steroids.