In what is still considered one of the most lopsided trades in baseball history, the Cardinals acquired a future first-ballot Hall of Famer in Brock. The Cardinals, in eighth place in the National League when they landed Brock, claimed a division title on the final day of the regular season. Brock then helped lead the Cardinals to the first of two World Series championships that they won with him on the club.
Brock hit .348 and stole 33 bases in 103 games with the Cardinals during that '64 season. Between 1966-1974, Brock led the league in stolen bases nine times, and, in 1977, he broke Ty Cobb's record to become baseball's stolen base king. He finished with 938 during his 19-year playing career.
2. July 29, 2002: Cardinals receive third baseman Scott Rolen, right-hander Doug Nickle and cash from the Phillies for infielder Placido Polanco, left-hander Bud Smith and right-hander Mike Timlin.
Rolen had some of the most successful seasons of his career during his six-year stay in St. Louis. Though the Cardinals' 2002 team fell in the NL Championship Series, Rolen signed an extension with the Cardinals after the season and helped the team get to the World Series in 2004 and '06. St. Louis won the '06 Fall Classic.
While with St. Louis, the third baseman won four of his eight Gold Glove Awards and represented the Cardinals in the All-Star Game four times. He finished fourth in the MVP voting in 2004, a season in which he batted .314 with 34 homers and 124 RBIs.
3. July 31, 1997: Cardinals receive first baseman Mark McGwire from the Athletics for right-hander Eric Ludwick, right-hander T.J. Mathews and right-hander Blake Stein.
McGwire never helped the Cardinals advance to the World Series during his five seasons with the organization, but he did draw flocks of people to the ballpark and help reenergize baseball from the 1994 work stoppage with his power surge.
A year after arriving from Oakland, McGwire shattered Roger Maris' season home run mark when he hit 70. McGwire then hit 65 homers in 1999. He was a three-time All-Star with the Cardinals and later became the organization's hitting coach.
4. June 7, 1981: Cardinals receive right-hander Joaquin Andujar from the Astros for outfielder Tony Scott.
Andujar, who vacillated between the rotation and bullpen while with Houston, arrived in St. Louis in 1981 and was used almost exclusively as a starter during his five-year stay. He was a 20-game winner for the Cardinals twice and went 3-0 during the 1982 postseason, which ended with the Cardinals celebrating a World Series championship.
5. July 24, 2009: Cardinals receive outfielder Matt Holliday from the Athletics for right-hander Clayton Mortensen, first baseman Shane Peterson and infielder Brett Wallace.
It took parting ways with a promising prospect to land Holliday, but the Cardinals have been pleased with the payoff. Holliday hit .353 in 63 games after the trade, helping get the Cardinals into the '09 postseason. Though the Cardinals were knocked out in the NL Division Series, Holliday's positive first impression of the organization was integral in his decision to re-sign with the Cardinals after the season. Two years later, Holliday celebrated a World Series title with the Cardinals.