 Located along the western shores of Lake St. Clair and the St. Clair River, the county was named for them by European-American settlers.The name is sometimes mistakenly attributed to honoring Arthur St. Clair, an American Revolutionary War General and Governor of the Northwest Territory, but it was established long before he was considered a notable figure.The earlier spelling of the lake's name may have been conflated with English practice and the name of the general, as several political jurisdictions near the lake and the river, such as St. Clair County, St. Clair Township, and the cities of St. Clair and St. Clair Shores, share this spelling.