At that point, major league clubs owning part or all of some minor league clubs was not unusual. Nor was the practice of placing players with minor league clubs for a few years to prepare them for the majors that uncommon, although it was done on a player-by-player basis for players who were expected to be brought up to the majors after a period of time. Rickey's plan was on a larger scale. He was the first set up a hieracrchical system for player developement, with teams at all levels. Players would move up the chain, with only the best making it to the majors.
By 1926, the system paid its first dividends, as the Cards won their first World Championship since the days of the Browns in the 1880s. The 1926 club featured a lineup dominated by players who came up through the burgoning system - Jim Bottemly, Chick Hafey, Taylor Douthit, Tommy Thevenow, Les Bell, Ray Blades, Flint Rhem, and Bill Hallahan, to name a few.
By the end of the twenties, the Cardinals controlled all or part of between 5 and 10
clubs, while the majors as a whole owned or controlled 29 minor league clubs. In
the 1930s, the Cards system reached its maximum extent, topping out at bewteen 25
and 35 clubs (depending on which sources you believe) late in the decade. This talent
pool fuelled the Cards to their first World Series title in this century in 1926
and ensured continued success through the next two decades. The success of the
Cardinals farm system may best be illustrated by the 1942 World Championship team,
which had only two players who were not developed in the Cardinals farm system.
In addition, the Cardinals were able to trade or sell excess talent from their
system to improve the club. (Rickey received a percentage of all player sales, which
probably contributed in part to the number of sales during this period.)
The size of the farm system shrunk down to less than ten clubs during the war years of 1943-1945. In the latter half of the 40s and well into the 50s, the Cards maintained at least 15 clubs in the minors, continuing the practice that had made the team a dominant club in the Natinal League. (One of the few franchises with as many or more clubs than the Cardials throughout the 40s and 50s was the Dodgers - then under Branch Rickey - who also had a fair amount of success during that time span.) By 1961, all but one major league club had trimmed back their farm system to under 10 teams (that club, the Dodgers, trimmed down below ten in 1962), and through the 60s most clubs maintained between 5 and 9 farm clubs each year. The Cards reached a low of 5 clubs in 1963, and again from 1974-1976 and 1979-1980. For most of the 1980s and 1990s they maintained seven or eight clubs, and in 1996 they dropped to the current level of six clubs (AAA, AA, 3 A, Rookie)
| Columbus (American Association) | 1926-1954* |
| Omaha (American Association) | 1955-1959* |
| Rochester (International League) | 1927-1960* |
| San Juan** (International League) Charleston (International League) | 1961 |
| Atlanta (International League) | 1962-1963 |
| Jacksonville (International League) | 1964-1965 |
| Tulsa (Pacific Coast League) | 1966-1968 |
| Tulsa (American Association) | 1969-1976 |
| New Orleans (American Association) | 1977 |
| Springfield (American Association) | 1978-1981 |
| Louisville (American Association) | 1982-1997 |
| Memphis (Pacific Coast League) | 1998-Present |
| Houston (Texas League) | 1925-1942 1946-1958* | |
| Tulsa (Texas League) | 1959-1965 | |
| Arkansas Travelers (Texas League) | 1966-2000 | |
| New Haven Ravens (Eastern League) | 2001 |
* I'm not sure at what point this became classified as AA, but I'm pretty sure it was the AA club by the 1960s. I also don't know if there were other AA clubs at any point. Arkansas was the only one from the mid-1960s onward, as far as I can tell.
| St. Petersburg Cardinals (Florida State League) | 1966-1996 |
| Potomac Cannons* (Carolina League) | 1997-Present |
| Springfield (Midwest League) | 1982-1993 |
| Madison (Midwest League) | 1994 |
| Peoria Chiefs(Midwest League) | 1995-Present |
| Erie (New York-Penn League) | 1981-1987 |
| Hamilton, Ontario (New York-Penn League) | 1988-1992 |
| Glenn Falls (New York-Penn League) | 1993 |
| New Jersey Cardinals (New York-Penn League) | 1994-Present |
| Sarasota (Gulf Coast League) | 1964-1976 |
| Gastonia (Western Carolina League) | 1977-1979 |
| Gastonia (South Atlantic League) | 1980-1982 |
| Macon (South Atlantic League) | 1983 |
| Savanah (South Atlantic League) | 1984-1995 |