The Charter Township of Union is located in the southeast part of Isabella County and in middle of Michigan’s lower peninsula. Geographically, the adjacent City of Mount Pleasant looks like an island near the middle of the Township. This proximity provides numerous opportunities for cooperative planning and provision of services.

Union Township traces its history and its name to the Civil War. A month before the first shots of war rang out at Fort Sumter on the South Carolina coast, the patriotic County Board of Supervisors formally established Union Township on March 11, 1861. They left no doubt where they stood on the upcoming hostilities. They were on the Union side.

Once covered by pine and hardwood forest and the winter home of the Chippewa tribe, the area that became Union Township would also come to serve as a center of lumbering and the oil industry in Michigan during the latter part of the 19th century and well into the 20th century.

The first white settlers came to the Township in 1854 when pioneer John Hursh and his family arrived in the area. Isabella County was established in 1859. Various settlements in the 36 square miles of the original Township have long disappeared, or been absorbed by the City of Mount Pleasant. Mount Pleasant was designated the county seat in 1860, became a village in 1875, and became a city in 1889. The history of the City, and the Township that surrounds it on all sides, have been bound together since they were both founded.