Pomona, California, has a history shaped by Indigenous homelands, Mexican-era ranchos, railroads, citrus agriculture, civic growth, education, and changing neighborhoods. Today, that history is newly relevant as residents and local officials continue to identify and preserve places that tell the story of the city. For readers exploring Pomona history, the story is not only about what happened long ago. It is also about how the past remains visible in streets, buildings, institutions, and community memory.
Pomona Before It Became a City
Long before Pomona was incorporated, the valley was home to Indigenous communities associated with the Gabrielino/Tongva people. Spanish colonization reshaped the region after Mission San Gabriel was established, and the lands that later became Pomona were eventually included in Rancho San José during the Mexican period.
Rancho San José and Early Settlement
In 1837, Ygnacio Palomares and Ricardo Vejar received the Rancho San José land grant, which covered a broad area of what is now the eastern San Gabriel Valley and Pomona Valley. As California passed into American control, large ranch properties were gradually divided and sold. New settlers arrived, agriculture expanded, and small communities began to take shape.
One of those settlements was Spadra, west of modern downtown Pomona. For a time, Spadra benefited from stage travel and the Southern Pacific Railroad. As transportation patterns changed, commercial activity shifted toward the new Pomona townsite. The City of Pomona traces its development to this transition from ranch lands and small settlements into an organized agricultural community.
Railroads Helped Create Modern Pomona
The railroad was one of the most important forces in Pomona’s early growth. During the 1870s, rail connections made it easier for farmers and merchants to reach larger markets. A townsite developed around transportation routes, streets were laid out, businesses appeared, and Pomona began to establish itself as the commercial center of the surrounding valley.
The city’s name also reflected the agricultural hopes of its founders. Pomona was named after the Roman goddess associated with fruit and fruit trees, an appropriate choice for a community that would soon become closely identified with orchards and farming.
The Citrus Industry Changed the Landscape
By the late nineteenth century, citrus had become one of the defining industries of Pomona and Southern California. Orange and lemon groves spread across the valley, while packing houses, irrigation systems, railroad shipping, and agricultural businesses supported a growing regional economy.
Citrus shaped Pomona’s landscape and influenced employment, land values, advertising, commerce, and migration. Colorful fruit-crate labels marketed California produce across the country with images of sunshine, mountains, orchards, and abundance. The Pomona Public Library Digital Collections preserves thousands of citrus labels and historic images documenting this agricultural era.
Incorporation and the Growth of a City
Pomona incorporated in 1888. As the population increased, the community added civic buildings, schools, churches, commercial blocks, homes, and public institutions. Downtown became a center of shopping, entertainment, banking, and local government, while residential neighborhoods expanded outward from the city’s early core.
Architecture from different periods still reveals this development. Victorian-era houses, Craftsman homes, Spanish Colonial Revival buildings, commercial storefronts, and later twentieth-century structures illustrate how tastes and economic conditions changed. These buildings are one reason historic preservation is important to understanding Pomona today.
Fairplex and a New Civic Identity
The Los Angeles County Fair became another major part of Pomona’s identity during the twentieth century. The fairgrounds developed into what is now known as Fairplex, creating a regional destination associated with agriculture, exhibitions, entertainment, education, and public events. Its agricultural roots help explain how Pomona evolved from a farming center into a more urban community.
Downtown Pomona also changed as automobiles, new shopping patterns, and suburban development transformed Southern California. Some historic buildings were lost, while others survived through reuse, restoration, or renewed interest in the city’s architectural heritage.
Cal Poly Pomona and the Kellogg Legacy
Another major chapter developed on land connected to cereal entrepreneur W.K. Kellogg. Kellogg created an Arabian horse ranch in Pomona during the 1920s. The property later became closely tied to the development of Cal Poly Pomona.
According to Cal Poly Pomona’s history, the university’s Pomona campus grew from the Kellogg property and developed into a major public polytechnic university. The W.K. Kellogg Arabian Horse Center and Kellogg House connect the modern campus with an earlier period of Southern California ranch life, philanthropy, and agricultural education.
Postwar Pomona and Changing Neighborhoods
After World War II, Pomona experienced many of the same changes transforming cities across Southern California. Housing expanded, new neighborhoods were developed, automobile travel became increasingly important, and commercial activity spread beyond the traditional downtown area. Freeways and regional growth connected Pomona more closely to metropolitan Los Angeles.
These decades also changed the city’s demographics and cultural identity. New generations of residents brought different experiences, traditions, businesses, and institutions. Pomona’s history therefore cannot be understood only through major landmarks. Neighborhood streets, schools, community organizations, small businesses, and gathering places are also part of the historical record.
Why Pomona’s History Is Especially Relevant in 2026
Historic preservation is a particularly timely subject in Pomona. The city maintains a preservation program and recognizes historic districts and individual landmarks. In 2026, preservation discussions included a proposal involving a portion of Fairplex, showing how places associated with twentieth-century civic and agricultural history are still being evaluated for their long-term significance.
Preserving More Than Famous Buildings
The City of Pomona Historic Preservation program focuses on protecting architectural, historical, and cultural resources. Existing historic districts include areas such as Lincoln Park, Wilton Heights, and Hacienda Park. Their importance comes from groups of homes, streetscapes, landscaping, and architectural patterns that help explain how the city developed.
This approach encourages residents to look at familiar places differently. A commercial building, former packing facility, neighborhood house, theater, school, or public space may hold information about a particular period of growth even if it is not widely known outside the community.
Discovering Pomona’s Past Through Local Archives
One of the best ways to understand the city is through historic photographs and documents. The Pomona Public Library’s digital collections include nearly a thousand photographs documenting local development, along with collections focused on landmarks, homes, portraits, citrus production, postcards, and local publications.
These archives make it possible to compare familiar streets with earlier versions of the same places. They also preserve details that broad histories can overlook, including storefronts, transportation, clothing, agricultural work, neighborhood design, and everyday community life.
A History That Is Still Being Written
The history of Pomona, California, is a story of change. Rancho lands became farms and towns. Railroads supported a citrus economy. Orchards gave way to neighborhoods, institutions, highways, schools, industry, and new forms of commerce. At the same time, surviving buildings and community archives preserve evidence of earlier eras.
That combination of change and continuity makes Pomona an especially interesting place to study. Explore more stories, landmarks, neighborhoods, and local history through our Pomona history articles as the site continues documenting the people and places that shaped the city.