Editing Mercer County, Ohio (section)

==History==
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Mercer County was created in 1820 from land that had been attached to [[Darke County, Ohio|Darke]] and [[Shelby County, Ohio|Shelby]] counties. Land south of the [[Treaty of Greenville|Greenville Treaty Line]] was still part of Darke County. An act establishing and fully organizing Mercer County took place on January 2, 1824. In 1837 [[Van Wert County, Ohio|Van Wert County]] was detached and the county line established is the current northern border of Mercer County. In 1839 Celina was established as the [[county seat|seat]] of Mercer County; [[St. Marys, Ohio|St. Marys]] was the previous seat. In 1848 the area south of the Greenville Treaty Line to the current southern county line, was attached. When [[Auglaize County, Ohio|Auglaize County]] was formed, Mercer County's eastern border was moved {{convert|6|mi|km}} west with the exception of the area south of the Greenville Treaty Line. This created the sharp point at Mercer County's southeast corner and was the last county line modification.

In the mid to late 1800s, Mercer County became home to many German immigrant farming families. Many of these [[German American]]s had immigrated from northwestern Germany.