[6][7] Pleasanton is home to the headquarters of Safeway, Workday, Ellie Mae, Roche Molecular Diagnostics, Blackhawk Network Holdings, Veeva Systems, and Simpson Manufacturing Company.

The Amador-Livermore Valley, where Pleasanton is located, was home to tribes in the Ohlone language group, mainly speaking Chochenyo.

[10] Native people from the valley began to join Mission Santa Clara, founded in 1777, in small numbers by the 1790s.

[10] After Mexico independence from Spain in 1821, the missions were secularized, the Native people being emancipated and the land given in the form of ranchos to Spanish and Mexican colonists.

It was located on the lands of the Rancho Santa Rita[12] near the site of a Native American ranchera, around the Francisco Solano Alviso Adobe called El Alisal (The Sycamores),[13] one of the earliest houses built in the valley in 1844.

Alisal, nicknamed "The Most Desperate Town in the West", was one of the settlements located along La Vereda del Monte that was a haunt and refuge of bandits and desperados in the era following the beginning of the California Gold Rush.

[citation needed] Banditos such as Claudio Feliz and Joaquin Murrieta ambushed prospectors on their way back from the gold rush fields and then sought refuge in Alisal.

from San José to live on their ranch along with John Kottinger, an Austrian immigrant and a lawyer who had married into the family.

Its name was chosen in the 1860s by John W. Kottinger, an Alameda County justice of the peace, after his friend, Union army cavalry Major General Alfred Pleasonton.

[14] The town was once home to Phoebe Apperson Hearst, who lived in a 50-room mansion on a 2,000 acres (8.1 km2) estate, now the site of Castlewood Country Club.

[16][17][18] After World War II, Pleasanton changed from being primarily focused on farming and ranching to being a bedroom community and a place for corporate headquarters due to major growth of the Bay Area.

near the Livermore border is Shadow Cliffs Regional Park, a lake that permits swimming, fishing, and boating.

Pleasanton has been successful in attracting a number of corporate headquarters, such as those of Safeway, Blackhawk Network Holdings, Workday, Simpson Manufacturing, The Cooper Companies and Shaklee.

Despite an increase in office space vacancy rates in 2000–2004, economic development has remained strong through the middle of the decade.

Other companies with major operations in Pleasanton include Hitachi High Technologies America, Inc., Cisco Systems, QASource, Sage Software (Accpac, etc.

[26] According to the Bay East Association of Realtors, the median price of a detached single family home was $1,795,000 as of August 2021.

Beginning in the late 1990s, the Pleasanton Downtown Association organized the popular First Wednesday celebrations from May through September of each year.

Every Friday from June until September the PDA schedules different local bands to perform in the evenings at the Lions' Wayside Park off of First Street.

Located on its grounds, the Pleasanton Fairgrounds Racetrack was built in 1858, making it the oldest 1-mile (1.6 km) horse racing track in the United States.

[33] Because of the preservation of Pleasanton's historic downtown area, many examples of architectural styles dating back to the mid-19th century exist.

[36] Phoebe Apperson Hearst had the hacienda remodeled and expanded by architect Julia Morgan for use as her primary residence after her husband died.

The estate was built upon a 453-acre (1.83 km2) rancheria obtained in 1886 by George Hearst, who intended to use the location for a race horse farm.

[37] Its name was inspired by the circular, carved marble wellhead purchased by Phoebe and William in Verona, Italy and installed in the middle of the courtyard.

The original architect used the term "provincial Spanish Renaissance",[38] while Garnett wrote it would be more accurately called "Hispano-Moresque".

After Phoebe's death in 1919, William had the wellhead and other furniture and objects moved to Hearst Castle at San Simeon and sold the estate.

[41] The city council consists of: Karla Brown (mayor), Valerie Arkin, Jack Balch, Jeffrey Nibert, and Julie Testa.

This fact was first discovered with the excavations for Hacienda Business Park, revealing significant tribal artifacts and human skeletal remains.

[54] The city is served by two stations on the Bay Area Rapid Transit (BART) heavy rail system's Blue Line, which runs along the northern boundary of the city: The Altamont Corridor Express rail service stops near Pleasanton's downtown at Pleasanton Station.