ORANGE

American era

After the Mexican–American War, Alta California was ceded to the United States by Mexico with the signing of the Treaty of Guadalupe Hidalgo in 1848, and though many Californios lost titles to their lands in the aftermath, Grijalva's descendants retained ownership through marriages to Anglo-Americans.

Since at least 1864, Los Angeles attorneys Alfred Chapman and Andrew Glassell, together and separately, held about 5,400 acres (22 km2) along both sides of the Santiago Creek (Glassell also had a 4,000-acre (16 km2) parcel where Costa Mesa is today). Water was the key factor for the location of their townsite (bordered by Almond Avenue on the south, Lemon Street on the west, Glassell Street on the east, and Maple Avenue on the north). Glassell needed a spot he could irrigate, bringing water down from the Santa Ana Canyon and the quality of the soil may have influenced his choice. Originally, the community was named Richland, but in 1873 Richland got a new name.

In the book, Orange, The City 'Round The Plaza by local historian Phil Brigandi, it states, "In 1873 the town had grown large enough to require a post office, so an application was sent to Washington. It was refused, however, as there was (and is) already a Richland, California in Sacramento County. Undaunted, the Richlanders proposed a new name – Orange."

The small town was incorporated on April 6, 1888, under the general laws of the state of California. Orange was the only city in Orange County to be planned and built around a plaza, earning it the nickname Plaza City. Orange was the first developed town site to be served by the California Southern Railroad when the nation's second transcontinental rail line reached Orange County.

The town experienced its first growth spurt during the last decade of the 19th century (as did many of the surrounding communities), thanks to ever-increasing demands for California-grown citrus fruits, a period some refer to as the "Orange Era". Southern California's real estate "boom" of 1886–1888, fueled by railroad rate wars, also contributed to a marked increase in population. Like most cities in Orange County, agriculture formed the backbone of the local economy, and growth thereafter was slow and steady until the 1950s, when a second real estate boom spurred development. Inspired by the development of a region-wide freeway system which connected Los Angeles' urban center with outlying areas like Orange, large tracts of housing were developed from the 1950s to the early 1970s and continues today, albeit at a much slower pace, at the eastern edge of the city.

During the COVID-19 pandemic, the City of Orange approved the closure of North and South Glassell Street to open the Orange Plaza Paseo, where businesses located on each street could open socially-distant outdoor seating and patios. On December 8, 2020, the city council voted unanimously to continue to keep the street closed until state or local restrictions end or by council direction.