In 1492, Columbus landed in today's Haiti/Dominican Republic, believing that he was in Asia.
He was in fact the first European to discover the Americas.
This discovery marked a huge turning point for the Spanish, who went on the colonize the Americas.
They founded the first settlement on mainland Central America in 1510.
In 1512, Magellan sailed around the globe connecting America and Asia.
In 1513, the Spanish discovered the Isthmus of Panama, a narrow land passage connecting the Atlantic and Pacific, which would facilitate the movement of trade and people.
In 1521, they conquered the Aztec Empire.
In 1542, they conquered the Inca Empire.
California remained untouched by the Europeans, separated from their colonies by mountains, jungles and deserts.
The closest major European port was Acapulco, which actively traded with the Philippines (also a Spanish colony).
Massive galleons, called the Manila galleons, sailed back and forth over several months, carrying spices and porcelain in exchange for gold.
The Spanish were keen to find a faster route connecting America to Asia.
A popular thought was that there might be a passage to the North - so Cabrillo set off to explore, reaching as far as Point Reyes - but missed the San Francisco Bay because of the fog!
He died of gangrene on the way back, but he is considered the first European to have seen California.
He's remembered through many official buildings like schools and the Cabrillo Highway today. A replica of his ship was built in San Diego in 2015.