[3] A native of Clearbrook, Minnesota, Westrum was a stalwart defensive player for the New York Giants (1947–57) and, in his prime, a powerful right-handed hitter, although he had trouble making contact and hit for a low .217 career batting average.

[6][7] His two-run, eighth-inning home run against Ralph Branca on August 13 snapped a 1–1 tie and gave the Giants a 3–1 victory over the Dodgers.

[1][4][9] The two teams met in the 1951 National League tie-breaker series in which the Giants' season was climaxed by Bobby Thomson's Shot Heard 'Round the World, a three-run home run in the bottom of the ninth inning for a 5–4 win of the third and final playoff game.

[14] On September 29, 1957, manager Bill Rigney started all the Giants who had been on the 1954 World Series team in the ballclub's final game at the Polo Grounds; Westrum caught during the 9–1 loss to Pittsburgh.

[23] Westrum was pictured on the cover of the first issue of Sports Illustrated on August 16, 1954, along with Milwaukee Braves star Eddie Mathews and umpire Augie Donatelli.

But only 11 days later, Westrum was named the Mets' interim manager when Stengel, 75, fractured his left hip getting out of a car on July 25.

But his 1966 Mets escaped the basement for the first time in the franchise's five-year history when they finished ninth, one notch above the cellar, posting a record of 66 wins and 95 losses, a 16-game improvement over the previous season.

[3] The Mets were slowly developing an array of young pitchers in the minor leagues; however, apart from Tom Seaver, none arrived in time to help Westrum in 1967, when New York again finished tenth and last.

He was not able to post a winning record in his 1½ years as San Francisco's manager, although he came close when his team finished one game under .500 in 1975 and in third place in the National League Western Division.