[5] While the Bears achieved great success as the top farm team of the New York Yankees in the late 1950s, an earlier stint as a mid-level affiliate of the Pittsburgh Pirates (1952–54) served to introduce Howsam to Pirates' general manager Branch Rickey, the Baseball Hall of Fame executive, who had revolutionized baseball in his earlier career with the St. Louis Cardinals and Brooklyn Dodgers.

When that bid was turned down, he met with Lamar Hunt in the lobby of The Brown Palace Hotel[6] and founded the Denver Broncos—one of the eight charter members of the American Football League.

In the wake of the Continental League's demise, Rickey, then 80, rejoined the Cardinals in 1962 as a part-time but influential advisor to the team's owner, August A. Busch Jr.

In mid-August 1964, with the Cardinals seemingly about to finish well behind the first-place Philadelphia Phillies, Busch fired general manager Bing Devine and replaced him with Howsam[8]—reputedly at Rickey's urging.

[9] However, the team Howsam inherited ended up winning 30 of its last 44 games — including eight in a row from September 24–30 — and captured the NL pennant on the last day of the season, as the Phils collapsed.

[8] Furthermore, Howsam did not have an opportunity to make major changes to the team in his six weeks as general manager; his tenure began two months after the June 15 trade deadline then in effect and the Cardinals' 25-man roster remained virtually the same from August 17 through the World Series.

[10] Howsam installed popular Red Schoendienst as manager and he rebuilt the Cardinals infield, trading away veterans and team leaders Ken Boyer,[11] Bill White and Dick Groat in a bid for more pitching help.

[12][13] In 1966, Howsam acquired future Hall of Fame first baseman Orlando Cepeda from the San Francisco Giants on May 8 and right fielder Roger Maris[14] from the Yankees on December 8 during the winter interleague trading period.

As the long-term replacement for Boyer, Howsam and Schoendienst decided to stay in house and move Cardinal right fielder Mike Shannon to third base.

But in December 1966, a 13-member local ownership syndicate led by newspaper publisher Francis L. Dale purchased the Cincinnati Reds; one month later, on January 22, 1967, Howsam accepted the group's offer to become the club's new general manager.

Although many key parts of the Reds' dynasty — such as Pete Rose, Johnny Bench, Tony Pérez, Lee May and Tommy Helms — were already in place or in the organization in 1966, Howsam boldly promoted young pitchers such as Gary Nolan, Don Gullett and Wayne Simpson to the Major Leagues.

He also acquired record-setting reliever Wayne Granger and two talented young outfielders, Bobby Tolan and Alex Johnson, from the Cardinals.

[8][15] Then, in two masterful 1971 trades, Howsam acquired second baseman Joe Morgan (in a deal that included May and Helms) from the Houston Astros and outfielder George Foster from the Giants (for utility infielder Frank Duffy).

In Cincinnati, Morgan won consecutive NL Most Valuable Player awards in 1975–76 and earned credentials for membership in the Hall of Fame.

Foster won the 1977 NL MVP award when he belted 52 home runs for the Reds — the only player to crack the half-century HR mark in the 1970s or 1980s.

The Sporting News named Howsam Major League Executive of the Year for 1973; ironically, that season the powerhouse Reds dropped the NLCS to the underdog New York Mets.

Players were not allowed to have facial hair (a policy that continued long after Howsam left the team) and were required to wear their uniform pants and socks in a specific fashion.