Phelps County is a county located in south-central Missouri in the United States. According to the U.S. Census Bureau, it included the mean center of U.S. population in 2000. As of the 2010 census, the population was 45,156. The largest city and county seat is Rolla. The county was officially organized on November 13, 1857, and was named after U.S. Representative and Governor of Missouri John Smith Phelps.
Much of the county is included within the Ozark Highlands American Viticultural Area (AVA). Vineyards and wineries were first established in the county by Italian immigrants in Rolla. Since the 1960s, winemakers have revived and created numerous vineyards in Missouri and won national and international tasting awards.
The first Phelps County Court convened on November 25, 1857 in the John Dillon cabin. The historic courthouse was begun in mid-summer of 1860, used as a Union hospital during the American Civil War and served as the courthouse until February 1994, at which time all county offices were relocated in the new Phelps County Courthouse. The new courthouse was dedicated on May 22, 1994.
There is a Goodspeed's local history for this county, written in 1889, available free and searchable at: 
Searchable death certificates, with images, for deaths between 1910 and 1957, are available free online at  Searchable birth and death records for pre-1910 births/stillbirths/deaths are available free online at  Both of the above databases are from the Missouri State Archives.