[12] The original inhabitants of the area were members of the Native American Hahamog-na tribe, a branch of the Tongva Nation (part of the Shoshone language group) that occupied the Los Angeles Basin.

They lived on a diet of corn meal, acorns, seeds and herbs, fish, venison, berries, fruits and other small animals.

South Pasadena's adjacency to a natural fording place along the Arroyo Seco served as a gateway to travel and commerce for aboriginal peoples.

The first of these adobe structures became headquarters for General Flores and his staff in 1847 where they agreed to surrender to American forces, ending Mexican Colonial rule in California.

In February 1888, members of the southern portion of Pasadena attempted to gain more control over their own property and a vote for incorporation was made.

[15][16] On March 2, 1888, the city of South Pasadena was incorporated with a population slightly over 500 residents, becoming the sixth municipality in Los Angeles County.

With the completion of the Pacific Electric Short Line, putting the entire city within easy walking distance of the red car stations, South Pasadena also became one of the first suburbs of Los Angeles.

[18][19][20] "Mom and Pop" merchants populate the business district, and the Mission West area is a part of the original U.S. Route 66.

Of historical relevance is The Fair Oaks Pharmacy and Soda Fountain; also the Rialto Theater in downtown South Pasadena is a unique blend of Spanish Baroque and Egyptian stylings and was built in 1925.

Deeds, Bruce Almighty, Old School, The Ugly Truth, and License to Wed are just a few of the notable films shot on location in South Pasadena.

The proposed 1960s route would have sliced through the middle of the city, as well as through neighborhoods in El Sereno and Pasadena having an impact on nearly 1,000 homes in its path.

However, this incompletion cuts off a north–south route from the San Gabriel Mountains in the north to Long Beach in the south, as well as connecting the 710 to the 110, 134, and 210 freeways.

On July 19, 1999, United States District Court Judge Pregerson issued a preliminary injunction prohibiting defendants Caltrans, et al., from proceeding with the 710 Freeway Project.

South Pasadena has been cited five times on the National Trust for Historic Preservation's list of "Most Endangered Places".

The City of South Pasadena has filed a federal lawsuit citing failure to protect clean air, the environment and historic properties, and until the California Department of Transportation (Caltrans) completes a comprehensive new environmental study, this will bring additional delays to the 40-year-old project.

The Southern California real estate boom of the early 2000s caused those properties in South Pasadena alone to appreciate to a combined value of over $300 million.

SB-416 also prohibits funds from the sale of surplus properties in the SR 10 corridor from being used to advance or construct any proposed North State Route 710 tunnel.

State Assemblyman Chris Holden co-sponsored the bill and remarked after it was signed into law, "…the surface route of the 710 Freeway is not going to happen and everyone knows that and so these properties should then be put back into the community".

[28] Caltrans, however, maintains that the freeway extension/connections are needed for the overall benefit of the Southern California public and continues to fight for its completion.

In May 2017, the MTA board voted unanimously to withdraw its support for the 710 tunnel proposal, and to reallocate all funding previously earmarked for it to surface street and other improvements, effectively killing the project for the foreseeable future.

Subsequently, Assemblyman Chris Holden, along with State Senator Anthony Portantino, proposed similar bills effectively deleting the uncompleted portion from the Highway grid.

Adjacent cities are Los Angeles to the west and south, Pasadena to the north, San Marino to the east, and Alhambra to the southeast.

According to the 2010 United States Census, South Pasadena had a median household income of $85,058, with 6.7% of the population living below the federal poverty line.

[57] The Arroyo Seco (canyon, stream, and cultural landscape) offers a diverse range of experiences for walkers and more experienced hikers.