1938 World Series

The 1938 World Series matched the two-time defending champion New York Yankees against the Chicago Cubs, with the Yankees sweeping the Series in four games for their seventh championship and record third straight (they would win four in a row this time, and five in a row later from 1949–53).
Dizzy Dean, who had helped carry the Cubs to the National League pennant despite a sore arm, ran out of gas in the Series as the Yanks crushed the Cubs again, as they had in 1932. The Cubs did not win a meaningful game against the Yankees until a regular-season interleague series in 2003.
Yankee starting pitcher Red Ruffing won two games without a loss, although he gave up a record seventeen hits in eighteen innings pitched.
This was the first World Series at Wrigley Field since the bleacher reconstruction of 1937 which had significantly shortened the left-center field power alley.

http://en.wikipedia.org/wiki/1938_World_Series