North America:
* John Deere: United States (Iowa, Illinois, Georgia, Kansas, etc.)
* Case IH: United States (Illinois, Wisconsin, Iowa)
* New Holland: United States (Pennsylvania, New York)
* Agco: United States (Georgia, Minnesota, Nebraska)
* Kubota: United States (Georgia)
Europe:
* Claas: Germany
* Fendt: Germany
* Deutz-Fahr: Germany
* Massey Ferguson: United Kingdom
* Valtra: Finland
* New Holland: Italy
Asia:
* Kubota: Japan
* Yanmar: Japan
* Mahindra: India
* TAFE: India
* YTO: China
* Lovol: China
Other:
* Belarus: Belarus
* Rostselmash: Russia
* Zetor: Czech Republic
This is not an exhaustive list, but it gives you a general idea of where farm tractors are manufactured.
It's important to note that some manufacturers have production facilities in multiple countries. For example, John Deere has factories in both the US and Europe. Additionally, some brands, like New Holland, are owned by larger companies (CNH Industrial) that may have production facilities in various locations.