Shiawassee County takes its name from the Shiawassee River, which enters the county near the southeast corner, passes through the villages of Byron and Vernon, the cities of Corunna and Owosso, and from there flows north into the Saginaw Bay, leaving this county near the center of the northern boundary. The name of Shiawassee is derived from Indian lore, meaning “Rolling” or “Sparkling Waters.”
On the east is Genesee County; to the south lies Ingham and Livingston Counties, to the west, Clinton and to the north Saginaw. Shiawassee was established as a separate county by the proclamation of Governor Cass on September 10, 1822. Besides the present territory, it then included eight townships of Livingston and eight townships of Genesee. Fifteen years later the organization of new counties reduced Shiawassee to its present size.
Shiawassee County from east to west is approximately 22 ½ miles wide and from north to south is 24 ½ miles. Although it is believed that Indians were the first settlers of this section, there were traces as late as 1830, of an earlier culture. Throughout the county were many circular or oval mounds, the use and significance of which were never fully determined. Some were undoubtedly graves, as on opening human bones were found. One that was explored in 1829 bore the appearance of a fort.
The first documented non-native american to set foot in Shiawassee County, as early as 1795, was a Frenchman named Bolieu. He established himself near the present site of Saginaw for the purpose of trading with the Indians. A fellow countryman named Tremble soon followed. For a long time the two Frenchmen controlled the trade of the vast district of which this county was a small part. Gradually, however, other traders and trappers came in; and the Indian, often unconscious of the danger which threatened his race-civilization fought unavailingly against the invasion of his hunting ground.
The first session of the County Board of Supervisors was held in October of 1837. On October 7, 1839, the County Board of Supervisors convened at Corunna and accepted a block of land 300 feet square, donated by the County Seat Company and designated as the Public Square. Upon this plot the first Courthouse was erected and the present Courthouse now occupies this site. The first term of the Circuit Court for Shiawassee County was held December 4, 1837. The first session of the Probate Court was February 13, 1838.
Owosso, the largest city in the county, was the birthplace of several famous people, among them being former Governor Thomas E. Dewey of New York and James Oliver Curwood, author and conservationist. Other cities are Corunna, the county seat, Durand, Laingsburg and Perry. In addition to the six incorporated villages, there are several smaller unincorporated communities.