Jefferson is a city in, and the county seat of Greene County, Iowa, United States, along the North Raccoon River. The population was 4,182 at the time of the 2020 census. It is the home of the Mahanay Memorial Bell Tower, tall, located on the town square, and visible for miles. The tower is named for Floyd Mahanay, a businessman, philanthropist, and former resident. Jefferson is bisected east to west by the old Lincoln Highway (formerly U.S. 30). A new U.S. Route 30 is located approximately one mile to the north.
History
While platted and settled a few years earlier, "New Jefferson" was organized in the winter of 1855–56 and officially incorporated in January 1872. It began as a farming community and remains so today. The first settlers of the new city were the family of George S. Walton who built there in 1855. During the Civil War, Jefferson as well as Greene County contributed its sons to raising Company H, 10th Iowa Infantry (1861) and Company E, 39th Iowa Infantry (1862). The railway came to Jefferson in the decades after the Civil War. Jefferson's first mayor was Mahlon Head, elected in 1872. Jefferson's library was completed in 1904 through the generosity of the Carnegie library fund. The stretch of Lincoln Highway that runs through Jefferson was completed .
Geography
According to the United States Census Bureau, the city has a total area of , of which is land and is water.
Climate
According to the Köppen Climate Classification system, Jefferson has a hot-summer humid continental climate, abbreviated "Dfa" on climate maps.