The following is a timeline of the organizational changes in the National Basketball Association (NBA), including contractions, expansions, relocations, and divisional realignment. The league was formed as the Basketball Association of America (BAA) in 1946 and took its current name in 1949, when it merged with the National Basketball League (NBL). The histories of NBA franchises that were also members of the American Basketball League (ABL), NBL, National Pro Basketball League (NPBL), and American Basketball Association (ABA) are also included.
Timeline
1946–1949: BAA years 1946: Founding of the BAA The Basketball Association of America (BAA) was established with 11 teams (divided into Eastern and Western Divisions).
Team folded after this season † + 1946–47 BAA teamsEasternWesternBoston CelticsChicago StagsNew York KnicksCleveland Rebels†Philadelphia WarriorsDetroit Falcons†Providence SteamrollersPittsburgh Ironmen†Toronto Huskies†St. Louis BombersWashington Capitols
1947 The Cleveland Rebels, Detroit Falcons, Pittsburgh Ironmen, and Toronto Huskies folded. The Baltimore Bullets joined from the ABL and were placed in the Western Division. The Washington Capitols moved to the Western Division. First season in BAA * + 1947–48 BAA teamsEasternWesternBoston CelticsBaltimore Bullets*New York KnicksChicago StagsPhiladelphia WarriorsSt. Louis BombersProvidence SteamrollersWashington Capitols
1948 The Fort Wayne Pistons, Indianapolis Jets, Minneapolis Lakers, and Rochester Royals all joined from the NBL and were placed in the Western Division. The Washington Capitols moved back to the Eastern Division. The Baltimore Bullets moved to the Eastern Division.
First season in BAA * Only season in the league § Folded after this season † + 1948–49 BAA teamsEasternWesternBaltimore BulletsChicago StagsBoston CelticsFort Wayne Pistons*New York KnicksIndianapolis Jets§Philadelphia WarriorsMinneapolis Lakers*Providence Steamrollers†Rochester Royals*Washington CapitolsSt. Louis Bombers
1949–1966: BAA–NBL merger 1949: BAA–NBL merger The Indianapolis Jets and Providence Steamrollers folded. The BAA merged with the NBL to form the NBA. The BAA teams from the Western Division were moved to a newly created Central Division. The Anderson Packers, Denver Nuggets, Sheboygan Red Skins, Syracuse Nationals, Tri-Cities Blackhawks, and Waterloo Hawks joined from the NBL. All were placed in the Western Division, except the Nationals, who were placed in the Eastern Division. The Indianapolis Olympians joined as an expansion team and were placed in the Western Division. Team merged from NBL ^ First season in NBA * Folded after this season † Team merged from the NBL, but then jumped to the NPBL after this season § Team merged from the NBL, but then folded after this season ^† + 1949–50 NBA teamsEasternCentralWesternBaltimore BulletsChicago Stags†Anderson Packers§Boston CelticsFort Wayne PistonsDenver Nuggets^†New York KnicksMinneapolis LakersIndianapolis Olympians*Philadelphia WarriorsRochester RoyalsSheboygan Red Skins§Syracuse Nationals^St. Louis Bombers†Tri-Cities Blackhawks^Washington Capitols Waterloo Hawks§
1950 contraction The Chicago Stags, Denver Nuggets, and St. Louis Bombers folded. The Anderson Packers, Sheboygan Red Skins, and Waterloo Hawks transferred to the NPBL. The Pistons, Lakers, and Royals moved back to the Western Division and the Central Division was eliminated. The Washington Capitols folded mid-season.
Folded midway through this season † + 1950–51 NBA teamsEasternWesternBaltimore BulletsFort Wayne PistonsBoston CelticsIndianapolis OlympiansNew York KnicksMinneapolis LakersPhiladelphia WarriorsRochester RoyalsSyracuse NationalsTri-Cities BlackhawksWashington Capitols†
1951: Hawks relocate to Milwaukee The Tri-Cities Blackhawks relocated to Milwaukee to become the Milwaukee Hawks.
Folded after the 1952–53 season † + 1951–52 to 1952–53 NBA teamsEasternWesternBaltimore BulletsFort Wayne PistonsBoston CelticsIndianapolis Olympians†New York KnicksMilwaukee HawksPhiladelphia WarriorsMinneapolis LakersSyracuse NationalsRochester Royals
1953 and 1954 contraction The Indianapolis Olympians folded. The Baltimore Bullets folded after 14 games into the 1954–55 season. Folded midway through the 1954–55 season † + 1953–54 to 1954–55 NBA teamsEasternWesternBaltimore Bullets†Fort Wayne PistonsBoston CelticsMilwaukee HawksNew York KnicksMinneapolis LakersPhiladelphia WarriorsRochester RoyalsSyracuse Nationals
1955: Hawks relocate to St. Louis The Milwaukee Hawks relocated to St. Louis to become the St. Louis Hawks.
+ 1955–56 to 1956–57 NBA teamsEasternWesternBoston CelticsFort Wayne PistonsNew York KnicksMinneapolis LakersPhiladelphia WarriorsRochester RoyalsSyracuse NationalsSt. Louis Hawks
1957: Pistons and Royals relocate The Fort Wayne Pistons relocated to Detroit to become the Detroit Pistons. The Rochester Royals relocated to Cincinnati to become the Cincinnati Royals.
+ 1957–58 to 1959–60 NBA teamsEasternWesternBoston CelticsCincinnati RoyalsNew York KnicksDetroit PistonsPhiladelphia WarriorsMinneapolis LakersSyracuse NationalsSt. Louis Hawks
1960: Lakers relocate to Los Angeles The Minneapolis Lakers relocated to Los Angeles to become the Los Angeles Lakers.
+ 1960–61 NBA teamsEasternWesternBoston CelticsCincinnati RoyalsNew York KnicksDetroit PistonsPhiladelphia WarriorsLos Angeles LakersSyracuse NationalsSt. Louis Hawks
1961 expansion The Chicago Packers joined as an expansion team and were placed in the Western Division.
First season in NBA * + 1961–62 NBA teamsEasternWesternBoston CelticsChicago Packers*New York KnicksCincinnati RoyalsPhiladelphia WarriorsDetroit PistonsSyracuse NationalsLos Angeles Lakers St. Louis Hawks
1962: Warriors relocate and Chicago rebrands The Philadelphia Warriors relocated to San Francisco to become the San Francisco Warriors and moved to the Western Division. The Cincinnati Royals moved to the Eastern Division. The Chicago Packers renamed the Chicago Zephyrs.
+ 1962–63 NBA teamsEasternWesternBoston CelticsChicago ZephyrsCincinnati RoyalsDetroit PistonsNew York KnicksLos Angeles LakersSyracuse NationalsSan Francisco Warriors St. Louis Hawks
1963: Zephyrs and Nationals relocate The Chicago Zephyrs relocated to Baltimore and renamed the Baltimore Bullets. The Syracuse Nationals relocated to Philadelphia and renamed the Philadelphia 76ers.
+ 1963–64 to 1965–66 NBA teamsEasternWesternBoston CelticsBaltimore BulletsCincinnati RoyalsDetroit PistonsNew York KnicksLos Angeles LakersPhiladelphia 76ersSan Francisco Warriors St. Louis Hawks
1966–1976: Expansion era 1966 expansion The Chicago Bulls joined as an expansion team and were placed in the Western Division. The Baltimore Bullets moved to the Eastern Division.
First season in NBA * + 1966–67 NBA teamsEasternWesternBaltimore BulletsChicago Bulls*Boston CelticsDetroit PistonsCincinnati RoyalsLos Angeles LakersNew York KnicksSan Francisco WarriorsPhiladelphia 76ersSt. Louis Hawks
1967 expansion The San Diego Rockets and Seattle SuperSonics joined as expansion teams and were placed in the Western Division. The Detroit Pistons moved to the Eastern Division.
First season in NBA * + 1967–68 NBA teamsEasternWesternBaltimore BulletsChicago BullsBoston CelticsLos Angeles LakersCincinnati RoyalsSan Diego Rockets*Detroit PistonsSan Francisco WarriorsNew York KnicksSeattle SuperSonics*Philadelphia 76ersSt. Louis Hawks
1968 expansion and relocation The Milwaukee Bucks and Phoenix Suns joined as expansion teams. The Bucks were placed in the Eastern Division and the Suns in the Western Division. The St. Louis Hawks relocated to Atlanta to become the Atlanta Hawks.
1968–69 first season in NBA * + 1968–69 to 1969–70 NBA teamsEasternWesternBaltimore BulletsAtlanta HawksBoston CelticsChicago BullsCincinnati RoyalsLos Angeles LakersDetroit PistonsPhoenix Suns*Milwaukee Bucks*San Diego RocketsNew York KnicksSan Francisco WarriorsPhiladelphia 76ersSeattle SuperSonics
1970 expansion and realignment The league realigned into the Eastern and Western Conferences, with two new divisions each. The Atlantic and Central Divisions were added to the Eastern Conference, while the Midwest and Pacific Divisions were added to the Western Conference. The Buffalo Braves, Cleveland Cavaliers, and Portland Trail Blazers joined as expansion teams. The Braves were placed in the Atlantic Division, the Cavaliers in the Central Division, and the Trail Blazers in the Pacific Division. While most of the remaining teams were placed in the conference of the same name as their former division, the Atlanta Hawks moved from the Western Division to the Eastern Conference, while the Detroit Pistons and Milwaukee Bucks moved from the Eastern Division to the Western Conference.
First season in NBA * + 1970–71 NBA teamsEasternWesternAtlanticCentralMidwestPacificBoston CelticsAtlanta HawksChicago BullsLos Angeles LakersBuffalo Braves*Baltimore BulletsDetroit PistonsPortland Trail Blazers*New York KnicksCincinnati RoyalsMilwaukee BucksSan Diego RocketsPhiladelphia 76ersCleveland Cavaliers*Phoenix SunsSan Francisco Warriors Seattle SuperSonics
1971: Rockets and Warriors relocate The San Diego Rockets relocated to Houston to become the Houston Rockets. The San Francisco Warriors moved to Oakland to become the Golden State Warriors.
+ 1971–72 NBA teamsEasternWesternAtlanticCentralMidwestPacificBoston CelticsAtlanta HawksChicago BullsGolden State WarriorsBuffalo BravesBaltimore BulletsDetroit PistonsHouston RocketsNew York KnicksCincinnati RoyalsMilwaukee BucksLos Angeles LakersPhiladelphia 76ersCleveland CavaliersPhoenix SunsPortland Trail Blazers Seattle SuperSonics
1972: Royals relocate to Kansas City–Omaha The Cincinnati Royals left Cincinnati and split their home games between Kansas City, Missouri and Omaha, Nebraska, becoming the Kansas City–Omaha Kings. They moved from the Central to the Midwest Division. The Houston Rockets moved from the Pacific to the Central Division. The Phoenix Suns moved from the Midwest to the Pacific Division.
+ 1972–73 NBA teamsEasternWesternAtlanticCentralMidwestPacificBoston CelticsAtlanta HawksChicago BullsGolden State WarriorsBuffalo BravesBaltimore BulletsDetroit PistonsLos Angeles LakersNew York KnicksCleveland CavaliersKansas City–Omaha KingsPhoenix SunsPhiladelphia 76ersHouston RocketsMilwaukee BucksPortland Trail Blazers Seattle SuperSonics
1973: Bullets relocate The Baltimore Bullets relocated to the Washington, D.C. suburb of Landover, Maryland to become the Capital Bullets.
+ 1973–74 NBA teamsEasternWesternAtlanticCentralMidwestPacificBoston CelticsAtlanta HawksChicago BullsGolden State WarriorsBuffalo BravesCapital BulletsDetroit PistonsLos Angeles LakersNew York KnicksCleveland CavaliersKansas City–Omaha KingsPhoenix SunsPhiladelphia 76ersHouston RocketsMilwaukee BucksPortland Trail Blazers Seattle SuperSonics
1974 expansion The New Orleans Jazz joined as an expansion team and were placed in the Central Division. The Capital Bullets renamed the Washington Bullets.
First season in NBA * + 1974–75 NBA teamsEasternWesternAtlanticCentralMidwestPacificBoston CelticsAtlanta HawksChicago BullsGolden State WarriorsBuffalo BravesCleveland CavaliersDetroit PistonsLos Angeles LakersNew York KnicksHouston RocketsKansas City–Omaha KingsPhoenix SunsPhiladelphia 76ersNew Orleans Jazz*Milwaukee BucksPortland Trail Blazers Washington Bullets Seattle SuperSonics
1975: Kings play in Kansas City full-time The Kansas City–Omaha Kings abandoned playing in Omaha to become the Kansas City Kings.