Monrovia is the fourth oldest general law city in Los Angeles County and the L.A. Basin (after Los Angeles, Santa Monica, and Pasadena). Incorporated in 1887, Monrovia has grown from a sparse community of orange ranches to a residential community of 37,000.

Around 500 BC, a band of Shoshonean-speaking Indians established settlements in what is now the San Gabriel Valley. These native Americans came to be called the Gabrieliño Indians by early Spanish explorers, and are now referred to as theTongva. The Tongva were not farmers; they gathered wild seeds, berries, and plants along rivers and in marshlands. Abundant oaks in the Valley, such as Coast Live Oak and Interior Live Oak provided a staple of the Tongva diet: acorn mush made of boiled acorn flour.