Dade County, encompassing 504 square miles on the west slope of Missouri's Ozarks, was organized in 1841 in territory ceded by Osage tribes in 1808 and named for Maj. Francis L. Dade, killed in the Florida War with Seminoles in 1835. Early settled by Southern pioneers, it includes Greenfield, the county seat, laid out in 1841 on a plateau above Turnback Creek on land given by Matthias and Mary Allison, with rolling prairies to the west and wooded hills to the east. Ozark (Presby.) College stood there from 1881 to 1903 after being founded as an academy in 1870, and Ebenezer Presbyterian Church, built in 1854 and rebuilt in 1884, became the site where the Ozark Presbytery, including 25 counties, was organized in 1870. Divided during the Civil War, the county endured guerrilla raids, troop movements, and skirmishes, and in Oct., 1863, Union soldiers in Greenfield withdrew as Confederate General Joseph O. Shelby's troops approached and burned the courthouse; rebuilt in 1867, it was replaced in 1934. The Kansas City & Memphis R.R. (Frisco) crossed the county in 1881, and the county's economy centered on dairy, livestock, grain, and fruit farming, with brief mining for coal, zinc, and iron and more extensive lead mining. In 1874, the discovery of a 50,000-pound lead boulder led to the opening of Corry Mine and the founding of the boom town of Corry, while other mines also operated before lead mining ended in the early 1900's. Dadeville, first known as Crisp Prairie and Mellville, was settled about 1818 by Redden and John Crisp, burned in the Civil War, then rebuilt and renamed; Arcola was laid out in 1880; Crisp became a post office in the 1890's; and South Greenfield, Everton, and Lockwood were laid out along the railroad in 1881. In the 1880's, a number of Germans settled in and around Lockwood. Local landmarks include the William Penn log cabin in Dye Park at Everton, the first building to serve as a courthouse, nearby Dilday Mill, a so-called Spanish Fort near Greenfield built by prehistoric Indians, the interdenominational Sinners Union Church near Lockwood, and, in adjacent Cedar County, the site of Stockton Dam, which impounds the waters of the Sac River in Cedar and Dade Counties.