The first battle near Los Angeles, Cali. during the Mexican-American War in 1847 erupted on the river flowing between two former Mexican ranches, El Rancho Paso de Bartolo and Rancho San Antonio. But unlike the name of the battle suggests, the Battle of Rio San Gabriel happened on the Rio Hondo River near present-day Montebello.

The Battle of Rio San Gabriel and the Battle of La Mesa resulted in victories for the United States. Moreover, it helped the US defeat Mexico in 1848 as the War arrived on the land of Mexican rancho owners around the Rio Hondo River.

The Old San Gabriel River and the Rio Hondo River

The Rio Hondo River was once the San Gabriel River. The current San Gabriel River, which passes on the opposite side of I-605, didn’t exist until the 1860s, according to “Commodore Stockton’s Report,” featured in the Annual Publication of the Historical Society of Southern California.

The Great Flood of the 1860s assisted the formation of the San Gabriel River. The River comes from the San Gabriel Mountains, where Eldoradaville once was. The San Gabriel River destroyed the mining town as the River descended the ancient San Gabriel Mountains. 

In fact, in an 1888 map in the Library of Congress, the Rio Hondo River is referred to as ‘the Old San Gabriel River.”

It’s confusing; but it makes sense that it was the original San Gabriel River. Mission San Gabriel Arcangel was next to the Rio Hondo River before it was in San Gabriel. 

After the current San Gabriel River reportedly formed, the river’s name changed. The Old San Gabriel River became the Rio Hondo River. Curiously, the river closest to Rio Hondo College is the San Gabriel River, not the Rio Hondo River.

The Battle of Rio San Gabriel and Battle of La Mesa

During the Mexican-American War in 1847, only two battles took place in Southern California. Both battles happened the weekend of Jan. 8 through Jan. 10., 1847.

The Battle of Rio San Gabriel, El Rancho Paso de Bartolo and Rancho San Antonio

On Friday, Jan. 8, the first battle was fought on the west edge of El Rancho Paso de Bartolo, on the Rio Hondo River. 

Juan Crispin Perez owned El Rancho Paso de Bartolo. Crispin Perez became the owner of the Rancho in the decade before the Mexican-American War. Eventually, after the War, former Alta California Governor Pio Pico purchased part of the Rancho.

But in 1847, US forces moved west through El Rancho Paso de Bartolo towards Los Angeles. However, Mexican Californio troops stopped them. The Mexican troops waited on the opposite side of the Rio Hondo River in Rancho San Antonio.

The area where the Battle of Rio Hondo took place is roughly on the corner of Bluff Rd and Washington Blvd. Next to the landmark site is a line of palm trees that sway as the wind rushes past. Across the street, on the corner, is a dialysis center.

The Battle of Rio San Gabriel River landmark overlooks the Rio Hondo River. That’s roughly, more or less, where Mexican troops stopped. That’s the view they saw. But the landscape wasn’t yet covered with houses and an urban setting.

The San Gabriel River is now just a dry riverbed, covered in gray cement. It’s not an actual river with a momentary natural barrier of defense like it was during the Mexican-American War. Instead, it’s completely dry, but the surrounding trees and grass are all still green.

Still, the Rio Hondo River appears vast and extensive. It stretches north towards the San Gabriel Mountains and extends east towards the Puente Hills.

After the battle, US troops crossed the Rio Hondo River. They camped in Rancho San Antonio, near the battle site, according to an 1847 map archived in Map Collections from the University of Texas at Arlington.

The battle, which Mexico lost, is commemorated by a plaque surrounded by two cannons under a shade structure. In 1945, the site became a Historical Landmark. 

The Battle of La Mesa and the Takeover of Los Angeles

The next day, the Mexican-American War moved west to the present-day City of Vernon. The US very quickly gained traction towards Los Angeles, now the second biggest city in the US.

The Battle of La Mesa took place on the soil of Rancho San Antonio on Sat. Jan. 9. The former Rancho San Antonio land includes several present-day cities like Montebello, East Los Angeles, Commerce, and Vernon. 

There’s also a Historical Landmark marker for the Battle of La Mesa on Santa Fe Ave at City Hall.

The marker and site of the battle are less than fives miles away from where the Sleepy Lagoon Murder occurred in 1942. A year later, in 1943, the Zoot Suit Riots shook Los Angeles. 

Pachucos (Mexican-Americans) and Navy Sailors went to war with each other in a much different Los Angeles, for a far different reason, with still very similar overtones. 

The plaque mentions the Battle of La Mesa is also known as the Battle of Los Angeles. The name is more commonly a reference to a different battle. But by Sunday, Jan. 10, the US was in Los Angeles. 

The US conquest of Los Angeles in 1847 culminated in a single weekend. But the rest of the Mexican-American War continued in Central Mexico.

The Treaty of Cahuenga

The Mexican-American War concluded a year later, in Feb 1848, in Mexico. But the fighting had already ended in Alta California. 

Just three days after the Battle of La Mesa, the Treaty of Cahuenga, in the present-day Studio City neighborhood of Los Angeles at the Campo de Cahuenga, brought the war to end. The Campo de Cahuenga was where Universal Studios now sits. The historical site is honored by a museum across the amusement park.

The Mexican-American War officially came to an abrupt end in 1848 with the Treaty of Guadalupe Hidalgo. As a result, Los Angeles and California joined the US, in the process, a new Mexican history and identity were created.