Then on October 18, 1967, A.L. owners at last gave Finley permission to move the Athletics to Oakland for the 1968 season. According to some reports, Cronin promised Finley that he could move the team after the 1967 season as an incentive to sign the new lease with Municipal Stadium. The move came in spite of approval by voters in Jackson County, Missouri of a bond issue for a brand new baseball stadium, the eventual Kauffman Stadium to be completed in 1973. Then U.S. Senator Stuart Symington of Missouri blasted Finley on the floor of the Senate, calling Oakland “the luckiest city since Hiroshima.” When Symington threatened to have baseball’s antitrust exemption revoked, the owners responded with a hasty round of expansion. Kansas City was awarded an American League expansion team, the Royals. They were initially slated to begin play in 1971. However, Symington was not willing to have Kansas City wait three years for another team, and renewed his threat to have baseball’s antitrust exemption revoked unless the teams began play in 1969. The owners complied.

The 1972 World Series matched the American League champion Oakland A’s against the National League champion Cincinnati Reds, with the A’s winning in seven games.

The 1973 World Series matched the defending champion Oakland A’s against the New York Mets with the A’s winning in seven games to repeat as World Champions.

The 1974 World Series matched the two-time defending champion Oakland A’s against the Los Angeles Dodgers with the A’s winning the Series in five games.

The 1989 World Series was played between the Oakland Athletics and the San Francisco Giants. The Series ran from October 14 through October 28, with the A’s sweeping the Giants in four games. It was the first World Series sweep since 1976. The four game sweep by the Athletics at the time would mark only the third time in World Series history that a team never trailed in any game (1963, 1966, and 2004 World Series being the only other times this occurred), and the first in the playoff era (post-1968).

On March 30, 2005, the Athletics were sold to a group fronted by real estate developer Lewis Wolff, although the majority owner is John J. Fisher, son of The Gap, Inc.’s founder. Wolff, though a Los Angeles businessman, had successfully developed many real estate projects in and around San Jose. The previous ownership had retained Wolff to help them find an adequate parcel on which to construct a new stadium. Because of Wolff’s background, rumors that he wanted to move the team to San Jose surfaced periodically upon his purchase of the team. However, any such plans were always complicated by the claims of the cross-bay San Francisco Giants that they own the territorial rights to San Jose and Santa Clara County.