Celebrations of the founding of the Mission have taken place since 1771 when the Mission was founded by the Fr. Junipero Serra and his helpers, Fathers Angel Fernandez de Somera and Pedro Benito Cambon. They continued through vibrant and flourishing times as well as more challenging days. From 1834 to 1862, the Mission celebrated Fiestas as a secular establishment. Then, in 1862, a grand Fiesta was held to celebrate the return of the San Gabriel Mission to the Catholic Church by President Abraham Lincoln.
The modern day Fiesta, formally known as La Fiesta de San Gabriel, started at the turn of the century around 1903. Celebrations have been held at various times from Thursday to Monday over Labor Day Weekend. Parades were held in the streets of San Gabriel for the Fiesta until the 1970s. A Royal Court consisting of a queen and at least two princesses are selected to reign over the festivities. The Fiesta has celebrated many milestone events in the 20th Century including the arrival of the Claretian Missionaries in 1908, establishment of Mission Elementary School by the Dominican Sisters in 1912, founding of Mission High School by the Claretian Missionaries and Dominican Sisters in 1949, and the completion of the full restoration of the Mission and Museum in 1993 (due to the 1987 Whittier Narrows Earthquake). In the late 1900s and now, La Fiesta is always celebrated on Friday, Saturday, and Sunday of Labor Day Weekend. Cultural, historic, and religious festivities coupled with live entertainment, a variety of international foods, amusements, and games make up our Fiesta. Attendance has continued to rise over the decades, and over 25,000 people attended La Fiesta in 2015.