San Francisco 49ers
The team was founded in 1946 as a charter member of the All-America Football Conference (AAFC) and joined the NFL in 1949 when the leagues merged. The 49ers were the first major league professional sports franchise based in San Francisco. The name "49ers" comes from the prospectors who arrived in Northern California in the 1849 Gold Rush. The team is legally and corporately registered as the San Francisco Forty Niners. The team began play at Kezar Stadium in San Francisco before moving across town to Candlestick Park in 1970 and then to Levi's Stadium in Santa Clara in 2014.
Oakland Raiders
There had been discussions for the Raiders to share Levi's Stadium with the San Francisco 49ers. However, the 49ers went ahead without the Raiders and broke ground on the $1.2 billion stadium on April 19, 2012 and have since sold $670 million worth of seats including 70% of club and luxury suites, making it unlikely that the Raiders would continue to explore the idea of sharing the stadium as they would now be secondary tenants with little to no commercial rights over the highly lucrative luxury suites.