JEFFERSON CITY, TN—Oshkosh Corp., the manufacturer of firetrucks, defense vehicles and concrete mixers, plans to build a new assembly plant here.

The company plans to renovate a former John Deere building. The roughly 500,000-square foot facility will house welding and fabrication operations and it is expected to be operational in 2019. The factory is expected to create more than 300 jobs over the next three years.