In aftermath of the September 11, 2001 terrorist attacks, the Yankees defeated the Oakland Athletics in the ALDS, and the Seattle Mariners in the ALCS. By winning the pennant for a fourth straight year, the 1998–2001 Yankees joined the 1921–24 New York Giants, and the Yankees teams of 1936–39, 1949–53, 1955–58 and 1960–64 as the only teams to win at least four straight pennants. The Yankees won 11 consecutive postseason series in this 4-year period.