Mexico's first Federal Building was appropriated in 1913 and served as the post office until 1967.  In 1968, it reopened as the Mexico-Audrain County Library.   The library was expanded in 1990 when the previous library building was moved and added on to the back.  Besides the full services of a library, the buildings also house an extensive volunteer-manned geneological society.

This building was constructed with the assistance of funds from the Carnegie Foundation in 1914 and moved to its present location in 1990.  On the left is the backside of the larger library structure.