The oak tree was called Oak of Peace because it was where two opposing armies (Mexican/Californios and American) came together to end the conflict of war. This spot is considered to be the birthplace of California, paving the way for it to become the 31st state of the United States.

In 1847, this grand 300 year-old oak was the most visible landmark on Rancho San Rafael. The 36,403-acre rancho, which had been granted to Don (Sir) José María Verdugo by the King of Spain, encompassed present-day Glendale, Burbank, La Cañada Flintridge, Los Feliz, Eagle Rock, Highland Park and West Pasadena. Verdugo raised cattle, horses and sheep and farmed fruits, vegetables and grapes. 

General Andrés Pico, commander of the Mexican army, had taken refuge at José Verdugo’s ranch after suffering significant losses against U.S. General Stephen Watts Kearny’s forces at the battle of San Pascual near Ramona. At San Rafael, he knew that his troops were safe to recover from battle and able to obtain food and water.  

Don Jésus Pico (a cousin of Andés Pico) was captured by Lt. Colonel Frémont's forces in the Salinas Valley as Frémont made his way to Los Angeles from Northern California. Jésus Pico had violated his parole and was court-martialed and sentenced to die by firing squad. Jésus' wife, along with their children, were allowed access to Lt. Col. Frémont, where she pleaded for her husband's life. Frémont called for Jésus Pico to be brought to him, and said “You were about to die, but your wife has saved you. Go thank her.”  Out of gratitude, Jésus Pico served Lt. Col. Frémont faithfully for the remainder of his time in California, including acting as Frémont’s emissary to the meeting with his cousin Andés Pico under the grand old oak.

On Jan 11, 1847, Frémont sent Jésus Pico with a letter including the terms of surrender to give to his cousin, General Andrés Pico. Jesus convinced the general that the U.S. forces were closing in on him and his men from both the north and the south and that they were much larger and stronger than his forces. 

Two days later, Lt. Col. Frémont and General Andrés Pico met at the Campo de Cahuenga, located on present-day Lankershim Blvd. across from Universal Studios, and signed the Treaty of Cahuenga, also called the Captivation of Cahuenga, to end the fighting of the Mexican-American war in California. A truce was ordered, commissioners were appointed, and a capitulation was agreed upon. The Treaty of Cahuenga ended the conflict, but California was fully secured to the United States by the treaty of Guadalupe Hidalgo in 1848.

Another important figure behind the Treaty of Cahuenga is Doña Bernarda Ruiz, who played a role in convincing Frémont to end the conflict with Californios. She appealed to her friend Don Jésus Pico to arrange a meeting for her with Lt. Col. Frémont. Frémont wrote in his memoir “I found that her objective was to use her influence to put an end to the war and to do so upon such just and friendly terms of compromise as would make peace acceptable and enduring”. 

The new Oak of Peace was planted in memory of this historic moment in 2023 by Don José Verdugo Chapter, National Society Daughters of the American Revolution and the City of Glendale. It replaces the original oak, which died of root rot in 1987.