Roofer in Palo Alto, CA

Prior to the arrival of Europeans, the Ohlone lived on the San Francisco peninsula; in particular, the Puichon Ohlone lived in the Palo Alto area. The area of modern Palo Alto was first recorded by the 1769 party of Gaspar de Portolá, a 64-man, 200-horse expedition setting out from San Diego to find Monterey Bay. The group trekked past the bay without recognizing it and continued north. When they reached modern-day Pacifica, they ascended Sweeney Ridge and saw the San Francisco Bay on November 2. Portolá descended from Sweeney Ridge southeast down San Andreas Creek to Laguna Creek (now Crystal Springs Reservoir), thence to the San Francisquito Creek watershed, ultimately camping from November 6-11, 1769, by a tall redwood later to be known as El Palo Alto.

In 1777, Father Junipero Serra established the Mission Santa Clara de Asis, whose northern boundary was San Francisquito Creek and whose lands included modern Palo Alto. The area was under the control of the viceroy of Mexico and ultimately under the control of Spain. On November 29, 1777, Pueblo de San Jose de Guadalupe (now the city of San Jose a few miles to the south of what was to be Palo Alto) was established by order of the viceroy despite the displeasure of the local mission. The Mexican War of Independence ending in 1821 led to Mexico becoming an independent country, though San Jose did not recognize rule by the new Mexico until May 10, 1825. Mexico proceeded to sell off or grant much of the mission land.

During the Mexican-American War, the United States seized Alta California in 1846; however, this was not legalized until the Treaty of Guadalupe Hidalgo was signed on July 4, 1848. Mexican citizens in the area could choose to become United States citizens and their land grants were to be recognized if they chose to do so (though many legal disputes arose over this).