Palo Alto is a California charter city located in the northwest corner of Santa Clara County, in the San Francisco Bay Area of California, USA. It is named after a tree called El Palo Alto. The city includes portions of Stanford University and is headquarters to a number of Silicon Valley high-technology companies, including Hewlett-Packard and Facebook. As of the 2000 census, the city had a total population of 58,598 residents. Palo Alto is located at 37° 25' 45"N 122° 08' 17"W / 37.429289, -122.138162). It is in the south-eastern section of the San Francisco Peninsula. It is bordered to the west by Menlo Park, to the north by East Palo Alto, and to the east by Mountain View and Los Altos. The southern border is made of Stanford, California (Stanford University) and Los Altos Hills.

Earliest recorded history stems from 1769, when Gaspar de Portolá noted an Ohlone settlement. This remains an area of known Indian mounds. A plaque is erected at Middlefield Road and Embarcadero Road to commemorate this area.

The city got its name from a tall tree, El Palo Alto, by the banks of the San Francisquito Creek bordering Menlo Park. You can still find half of this tree (the other half was destroyed when the creek flooded) along the foot bridge on Alma Street. A plaque recounts the story of a 63 man, 200 horse expedition from San Diego to the mission at Monterey from November 7–11, 1769. The group overshot and reached the bay instead. Regarding the bay as too wide to cross, the group decided to turn around near 'el palo alto.'

About 1827 Rafael Soto, tenth child and son of De Anza Expedition settler Ignacio Soto and María Bárbara Espinosa de Lugo of Alta California came to stay with Maximo Martinez at his great Rancho el corte de Madera for seven years, it was 13,316 acres. Located south of the San Francisquito Creek, west of today's I-280, it covered most of Portola Valley to Skyline Boulevard extending south to about Foothill College. Rafael and family settled in 1835 near the San Francisquito Creek near Newell & Middlefield. Selling goods to travelers in the area about 1830. His property, Rancho Rinconada del Arroyo de San Francisquito was granted in 1835 at a size of about 2,230 acres and reduced over time and claim. His wife, Maria Antnio Mesa, met with problems maintaining ownership. Their daughter María Luisa married (1) John Coppinger in 1839 who owned a large area west of the same creek, Rancho Canada de Raimundo. It began at Almbique Creek, the north border of el Corte de Madera, and extended north for 12,545 acres. Now part of Woodside, Bear Gulch Creek / Bear Creek flowed on his land in Portola Valley and present San Mateo County. It also abutted Buelna's grant near Skyline Boulevard and Matadero Creek. Upon his death, Maria inherited it and married later a visiting boat captain, (2) John Greer, who stumbled into the area. He owned a home on the property that is now Town & Country Village on Embarcadero & El Camino Real. Greer Avenue and Court are named for him.

To the west of Rafael Soto near El Camino and following the Creek was the next grantee in 1839, Antonio Buelna and wife Dona Maria Concepcion. To the south of the Sotos was another family, cousins and later grantee owners; the Robles brothers. Espanolos, Castilian, they said, and named Don Secundino and Teodoro. The older born in 1813 at Presidio Branciforte (Santa Cruz). Sons of a Mexiacan Army Californio. In 1849 they bought their 8,500 acres property from José Peña, his 1841 grantee of Rancho Santa Rita, named Rancho Rincon de Francisquito.

It was basically from San Francisquito Creek, Alpine Road and Bishop Ln. (behind Stanford Shopping Ctr.) & golf course. Then South along the Santa Cruz Foothills between Junipero Serra & Hwy 280 to the (Intersection of Matadoro Creek/ Hillview /Miranda) & then SW near the intersection of Page Mill & Arastradero Rd. where the Jone's House was), then east down Arastradero Rd. to the north property line of Alta Mesa Memorial Park and Terman Park. Follow the trail of what was once the old stage road over Adobe Creek / Yuegas Creek to El Camino Real & then east on San Abtonio Rd. to the Bay marshes passing over the RR and what was once the Jeffry's House & Stables. The property then went along the bay to the Embarcadero, a major boundary in the day. Then up to the Stanford University gates, up Galvez and along Campus way to the hills near the golf course. That's the Robles Rancho, about 80% of Palo Alto and Stanford University. So why aren't they historically famous? It was Spanish California! It was whittled down by 1863 through courts to 6,981 acres. Stories say their grand hacienda was built on the former meager adobe of José Peña near Ferne off San Antonio Road, midway between Middlefield and Alma St. These 2 boys did well. They later were forced to sell 250 acres in 1853 the present Barron Park, Matadero Creek and Stanford Business Park to Elisha Oscar Crosby ~ Creator of the term 'Mayfield'. Their hacienda hosted fiestas and bull fights. It was ruined in the 1906 earthquake and its lumber was used to build a large barn nearby which it is said lingered until the early 1950s. In 1880 Secundino Robles, father to twenty-nine children, still lived near present day Sears Dept. Store and was bounded on the south by Mariano Castro's grant across the street on San Antonio Road.

From 1846–1848, the United States and Mexico were at war, which concluded with U.S. acquisition of California and New Mexico. Mexican land grants became targets of the Americans settlers and tycoons. They were much more passive and had no real ability to confront De Anza and his men. Palo Alto was destined to be an early settlement but was reconsidered due to low creek levels. They marched on and set up a camp (Presidio) in present day San Francisco.

Many of the Spanish names in the Palo Alto area represent the local heritage and descriptive terms and former residents. Pena Court, Miranda Avenue, which was essentially Foothill Expwy was the married name of Juana Briones and the name occurs in Courts and Avenues others in Palo Alto to Mountain View in the quadrant where she owned vast areas between Stanford Univ., Grant Road in Mountain View and west of El Camino. Yerba Buena was to her credit. Rinconada was the major Mexican land grant name.

The township of Mayfield was formed in 1855, in what is now part of South Palo Alto. In 1886, Leland Stanford came to the town of Mayfield, interested in founding his university there, and creating a train stop near his school on Mayfield's downtown street, Lincoln Street (now named California Avenue). However, he had one condition: alcohol had to be banned from the town. Known for its 13 rowdy saloons, Mayfield rejected his requests for reform. This led him to drive the formation of Palo Alto, originally called University Park, in 1887 with the help of his friend Timothy Hopkins of the Southern Pacific Railroad who bought 740 acres of private land for the new townsite. Stanford set up his university, Stanford University, and a train stop (on University Avenue) by his new town. With Stanford’s support, saloon days faded and Palo Alto grew to the size of Mayfield. On July 2, 1925, Palo Alto voters approved the annexation of Mayfield and the two communities were officially consolidated on July 6, 1925. This saga explains why Palo Alto has two downtown areas: one along University Avenue and one along California Avenue. The Mayfield News wrote its own obituary four days later:

     It is with a feeling of deep regret that we see on our streets today those who would sell, or give, our beautiful little city to an outside community. We have watched Mayfield grow from a small hamlet, when Palo Alto was nothing more than a hayfield, to her present size … and it is with a feeling of sorrow that we contemplate the fact that there are those who would sell or give the city away.

Many of Stanford University’s first faculty members settled in the Professorville neighborhood of Palo Alto. Professorville, now a registered national historic district, is bounded by Kingsley, Lincoln, and Addison avenues and the cross streets of Ramona, Bryant, and Waverley. The district includes a large number of well preserved residences dating from the 1890s including 833 Kingsley, 345 Lincoln and 450 Kingsley. 1044 Bryant was the home of Russell Varian, co-inventor of the Klystron tube. The Lee DeForest laboratory site, situated at 218 Channing, is a California Historical Landmark recognizing DeForest's 1911 invention of the vacuum tube and electronic oscillator at that location. While not open to the public, the garage that housed the launch of Hewlett Packard is located at 367 Addison Av. Hewlett Packard recently restored the house and garage. A second historic district on Ramona Street can be found downtown between University and Hamilton Avenues.