![](https://www.vaco.org/wp-content/uploads/Buchanan-county-seal-2.png)
![](https://www.vaco.org/wp-content/uploads/Buchanan-county-seal-2.png)
County Courthouse
![](https://www.vaco.org/wp-content/uploads/2022/09/Buchanan16.png)
County Details
County Seat: Grundy
Year Organized: 1858
Total Square Miles: 503
2020 Population: 20,355
Persons/Square Mile: 40
County Structure
Government Type: County
Authority: Dillon’s Rule
Legislative Body: Board of Supervisors
Size of Legislative Body: 7