[4] The boundaries of Lenawee County were laid out by a proclamation of the Territorial Governor, Lewis Cass, on September 10, 1822.

The settlers, consisting of fifteen men, eleven women, and six children, all came from Jefferson County, New York along Lake Erie.

Brown and Evans, along with Austin Eli Wing, purchased land there and platted the village of Tecumseh in 1824.

This was accomplished by an act of the Territorial Legislature on June 30, 1824, although county government was not organized for another year and a half.

It moved its remaining production to a plant in Tupelo, Mississippi, where labor costs were lower because workers were unorganized.

Consolidated Biscuit Company of McComb, Ohio, agreed to buy the Products plant in 2008, pending an environmental review.

[18] The State of Michigan Department of Environmental Quality (MDEQ) awarded the City of Tecumseh $2,000,000 in funding to aid the developer in cleanup efforts.

[19][20] At the end of 2018 demolition at the site was nearly complete and cleanup efforts were underway with new industrial building construction planned for 2019.

[21] Overall, the City of Tecumseh's economy has more than 250 businesses, ranging from Tier 1 Automotive Suppliers to small, locally owned bakeries and shoe stores.

The downtown along Chicago Boulevard is thriving with businesses ranging from antiques, breweries and wineries, retail, restaurants, customer jewelers, locally owned department stores and more.

In 2010, the city began hosting the Tecumseh Ice Sculpting Festival in the downtown area on the penultimate weekend in January.

[22] Another festival is Appleumpkin (held the second weekend in October to celebrate harvest); it attracts approximately 30,000 tourists annually from around the region.

[23] The city of Tecumseh holds several other events each year, such as the Classic Car and Bike Show,[24] Divas at Dusk,[25] Holiday Open House,[26] Annual Pet Parade[27] and Sidewalk Sales.

[34][35][36] Tecumseh students have access to the Lenawee Intermediate School District (LISD) and the Southern Michigan Center for Science and Industry.

Tecumseh Public Schools seeks to provide myriad educational opportunities to create a work-ready workforce, including industry-specific programs to focus on the needs of area businesses.

[38] A horse, Don Juan, that belonged to General George Armstrong Custer is buried in Tecumseh.