Toyota is set to mark the 20th anniversary of when it started building what is now a 5,000-worker assembly plant in southwestern Indiana.
Construction began in May 1996 on the factory near Princeton, about 150 miles from Indianapolis. Toyota spent about $1.2 billion on the complex by the time it started production of full-size Tundra pickup trucks in late 1998.
Toyota says the factory has since produced 4.3 million vehicles, including Highlander and Sequoia SUVs and Sienna minivans.
Company executives are set to join state and local officials in a ceremony Wednesday at the factory's visitor center about 25 miles north of Evansville.
Toyota has expanded the plant several times, most recently with a $100 million project announced in 2014 to boost Highlander production.