On June 15, 1964, one of the most lopsided trades in the history of Major League Baseball was made when Cardinals General Manager Bing Devine dealt Ernie Broglio, Doug Clemens, and Bobby Shantz to the Chicago Cubs, in return the Cardinals got Jack Spring, Paul Toth, and a 24 year old kid by the name of Lou Brock. On the surface it looked like the Cubs got the better end of the deal. Broglio was a former 20 game winner and it looked like they had landed a true frontline starter for their rotation. Brock had just two big league seasons under his belt at the time of the trade, he was a hot prospect with blazing speed and great baserunning skills but struggled at the plate a bit which led the Cubs organization to making the deal that sent him to St. Louis. Broglio's best days were behind him, he spent two and a half seasons in Chicago posting a 7-19 record while Brock spent the next 16 years in St. Louis and forged a career that led to Cooperstown. 4 months to the day that Brock was traded to the team the Cardinals won the World Series in 7 games over the New York Yankees, he would win another title with the team in '67. When Brock retired in 1979 he was the all time leader in stolen bases with 938 and had collected 3,023 hits in the big leagues.
MLB Network did a great piece about the trade, it's narrated by St. Louis' own Greg Amsinger: