In 1800, governor Arthur St. Clair made Trumbull County (named for Connecticut Governor Jonathan Trumbull). He named the smaller town of Warren as its "county seat". In 1813, Trumbull County was divided into townships, with Youngstown Township being a big part of what became Mahoning County. The village of Youngstown was incorporated in 1848, and in 1867 Youngstown was chartered as a city. It became the county seat in 1876.