600px-Bolivia_Departments
Bolivia is a unitary state consisting of nine departments. Departments are the primary subdivisions of Bolivia, and possess certain rights under the Constitution of Bolivia. Each department is represented in the federal Plurinational Legislative Assembly—a bicameral legislature consisting of the Senate and the Chamber of Deputies. Each department is represented by four Senators, while Deputies are awarded to each state in proportion to their total population.

This is a contemporary map but postal historians should still find it useful…