Throughout basketball's history, no part of the game has been more monitored than the act of fouling an opponent. In basketball's early days, a player's second foul would mean removal from the game until the next field goal was made. If a team committed three consecutive fouls, the opposition would be awarded a field goal. Beginning in 1894 players were given a free throw when fouled. Beginning in 1908 players who committed five fouls were disqualified from the game. Based on the severity of the foul, the rules were soon amended so that players were awarded either two shots or one shot plus a bonus shot, which was attempted only if the first shot was made. The rules also determined that an offensive player could commit a foul by playing too aggressively.

In 1892 Lithuanian-born physical education teacher Senda Berenson Abbott introduced basketball to women, at Smith College in Northampton, Massachusetts. Because it was believed that Naismith’s version of the game could be too physically demanding for women, Berenson Abbott made the following changes to the game: The court was divided into three equal sections, with players required to stay in an assigned area; players were prohibited from snatching or batting the ball from the hands of another player; and players were prohibited from holding the ball for longer than three seconds and from dribbling the ball more than three times.

Basketball's growth spread in the United States and abroad through Young Men's Christian Associations (YMCAs), the armed forces, and colleges. Due to its simple equipment requirements, indoor play, competitiveness, and easily understood rules, basketball gained popularity quickly. In May 1901 several schools, including Yale and Harvard universities and Trinity, Holy Cross, Amherst, and Williams colleges, formed the New England Intercollegiate Basketball League. The development of collegiate leagues and conferences brought organization and scheduling to competition, and formal league play created rivalries. More importantly, collegiate leagues became a critical training ground for officials.

By the early 1900s basketball was played at about 90 colleges—most of them located in the East and Midwest. In 1905 teams from the University of Minnesota and the University of Wisconsin traveled to New York to challenge Eastern League champion Columbia University. Columbia’s “Blue and White Five” defeated both Midwestern teams, and the idea of an intercollegiate championship was born. By 1914 more than 360 colleges offered basketball, and the sport had spread heavily into the Midwestern states.

In 1915 the Amateur Athletic Union of the United States (AAU), the NCAA, and the YMCA formed a committee to standardize rules, and during the next ten years a number of regional conferences were formed. Games between top regional teams were sometimes awarded national champion status by the press, but an official championship tournament was still many years away. Travel and scheduling difficulties and continued regional rule differences slowed the organization of a tournament that could impartially produce a national champion.

The first national collegiate tournament was held in Kansas City, Missouri, in 1937. The teams in this tournament, however, were all from the Midwest. New York, with a large fan base that generated travel funds, was the site of the NIT tournament, which was the first truly national collegiate tournament. The first NIT was held at the end of the 1937-38 season.

The NIT was promoted by members of the Metropolitan Basketball Writers Association—a New York City sportswriters’ group. In 1939 a group of coaches from the National Association of Basketball Coaches (NABC), fearing Eastern bias, organized and sponsored the first NCAA national tournament. In this tournament the University of Oregon defeated Ohio State University. The NCAA took sole control of the organization of its tournament after that first year. For the next decade, the NCAA and NIT tournaments competed to become the universally recognized national championship tournament, with the NCAA eventually winning out.

The NCAA tournament's original format, used for its first 12 years, divided the country into eight districts, each with a regional selection committee sending a team to the eight-team tournament. As the tournament gained importance, the field gradually enlarged to its present size of 64, made up of champions from a number of conferences, in addition to other successful teams.

Professional basketball began in 1896 at a YMCA in Trenton, New Jersey. A dispute between members of the YMCA team and a YMCA official led to the players forming a professional team and playing for money. In 1898 a group of New Jersey newspaper sports editors founded the National Basketball League (NBL). The NBL consisted of six franchises from Pennsylvania and New Jersey. Stars of this league included Ed Wachter, who played in about 1,800 professional games, and Barney Sedran, who played on 10 championship teams in 15 years.

The Buffalo Germans, a team that won 111 straight games between 1908 and 1911, and the Original Celtics, a team that pioneered many tactics in basketball, including the development of the zone defense, were extraordinarily successful professional teams in the early 20th century. The first successful national professional league was the American Basketball League (ABL), which lasted from 1925 to 1931. The New York Renaissance, a team made up of black players, dominated the 1930s. The Rens, as the team was called, were the best team of the era, winning 88 consecutive games during one stretch. Another all-black team with similar success was the Harlem Globetrotters. The Globetrotters were founded in 1927 as a competitive team, but through the years they became known for their basketball acrobatics and humorous routines.

Although most basketball players were men, 37 states offered high school varsity basketball for women by 1925, and in 1926 the AAU formed a national tournament for women's teams. This enabled women to showcase their basketball skills after scholastic play was finished, and also to gain employment at companies that sponsored their own AAU teams. Notable players from this era of women's basketball include Babe Didrikson, Alline Banks Sprouse, and Nera White, who was one of the first two female players elected to the Basketball Hall of Fame. In 1938 the three-court game was changed to a two-court game, with six players on a team (three on offense and three on defense). Players were still prohibited from straying from their assigned areas.

In the mid-1930s another professional league called the National Basketball League (NBL) was founded, taking the same name as the earlier NBL, which had ceased operation some years before. In 1946 a group of executives in New York City formed yet another new professional basketball league, known as the Basketball Association of America (BAA). This new circuit was a direct competitor with the new NBL, with teams in New York City; Boston, Massachusetts; Philadelphia, Pennsylvania; Chicago, Illinois; and Detroit, Michigan. Just before the 1948-49 season, the four strongest teams in the NBL—those from Minneapolis, Minnesota; Rochester, New York; Fort Wayne, Indiana; and Indianapolis, Indiana—joined the BAA. The following season, the NBL's six surviving teams also joined the BAA, forming a three-division league that was renamed the National Basketball Association (NBA). After the 1949-50 season the NBA reduced its size and established two divisions, the forerunners to the Eastern and Western conferences that were established after the 1969-70 season.

In the late 1940s and early 1950s, the Minneapolis Lakers, led by center George Mikan and coached by John Kundla, won five NBA championship titles (1949, 1950, 1952-1954). In the 1950s guard Bob Cousy and forward Bob Pettit had the greatest individual impact on professional basketball. Cousy, nicknamed the Houdini of the Hardwood because of his ball-handling skills, led the NBA in assists eight straight years (1953-1960) and guided the Boston Celtics to six NBA titles (1957, 1959-1963). Pettit finished his career with a remarkable 26.4 points per game (ppg) average while leading the St. Louis Hawks to appearances in the NBA championship finals in 1957, 1958, 1960, and 1961, with the Hawks winning the title in 1958.

The Celtics dominated the NBA from 1957 to 1969. During this 13-season period, the team, coached mostly by Red Auerbach, won 11 NBA titles (1957, 1959-1966, 1968, 1969), including 8 consecutively. The Celtics had many stars, but center Bill Russell was arguably the greatest. In his 13-season career Russell averaged 15.1 ppg and 22.5 rebounds per game (rpg). Another dominant center of the time was Wilt Chamberlain. Chamberlain played for the Philadelphia Warriors, San Francisco Warriors (the team moved west in 1962), Philadelphia 76ers, and Los Angeles Lakers. He scored 100 points in a single game in 1962 and averaged 50.4 ppg for the 1961-62 season. Neither record has ever been approached by another player. Top guards of the 1960s included Oscar Robertson of the Milwaukee Bucks, Jerry West of the Los Angeles Lakers, and Walt Frazier of the New York Knicks.

The University of California, Los Angeles dominated college basketball from 1963 to 1975. Coached by John Wooden, UCLA won ten national championships during this time (1964, 1965, 1967-1973, 1975), including seven consecutively. From 1971 to 1974, UCLA won 88 consecutive games, an NCAA record. Wooden's UCLA teams featured great players such as center Bill Walton, guard Gail Goodrich, forward Jamaal Wilkes, and forward Marques Johnson. The best player to emerge from UCLA was center Kareem Abdul-Jabbar, who was born Lew Alcindor. Abdul-Jabbar led UCLA to three straight NCAA titles from 1967 to 1969. As a professional he led the Milwaukee Bucks to an NBA title in 1971, and he led the Los Angeles Lakers to five NBA titles in the 1980s (1980, 1982, 1985, 1987, 1988). Known for his famous sky-hook shot, Abdul-Jabbar played 20 seasons in the NBA and retired as the league's leading career scorer, with 38,387 points.

For two decades after its founding, the NBA was the only major professional basketball league. But in 1967 the American Basketball Association (ABA) was formed. The league became known for the flashy playing style it encouraged and the distinctive red, white, and blue basketballs it used. The ABA convinced several NBA players to switch leagues, often for lucrative contracts. Probably the best player in the ABA was guard and forward Julius Erving, who later starred in the NBA. The ABA disbanded in 1976, with several of its teams joining the NBA.

In the late 1970s, the NBA experienced difficulty: The game was perceived as dull, the league's ticket sales decreased, revenue declined, and television ratings were as low as they had ever been. In March 1979, however, two collegiate players, forward Larry Bird of Indiana State University and guard Magic Johnson of Michigan State University, helped revive public interest in basketball. The two players, the stars of their teams, faced each other in the 1979 NCAA championship game, won by Michigan State. Both players went on to have distinguished NBA careers. In the 1980s Bird helped revitalize the Boston Celtics franchise, leading the team to three NBA titles (1981, 1984, 1986). Johnson did the same in Los Angeles, as he and Abdul-Jabbar guided the Lakers to five NBA championships.

In the late 1980s the Detroit Pistons emerged as a powerhouse team, featuring stars such as guard Isiah Thomas and forward Dennis Rodman. Detroit reached the NBA Finals in 1988, 1989, and 1990, capturing the title during the latter two years. Increased interest in the professional game carried over to collegiate basketball as well, as the NCAA tournament became more popular than ever.

Dramatic changes in women's basketball occurred in the late 1960s. In 1966 unlimited dribbling became legal, and in 1969 the first five-player full-court game was played. The five-player form became the official game in women's basketball in 1971. Women's basketball is now played with virtually the same rules, regulations, and styles as men's basketball, although the women use a slightly smaller ball at many levels, including college. With the changes of the late 1960s, women's basketball began a period of tremendous growth, and in 1971 the Association for Intercollegiate Athletics for Women (AIAW) was founded, offering a national college basketball tournament for women.

The women’s game gained strength in the late 1970s after a law called Title IX was increasingly enforced, helping strengthen women's basketball programs. The law, passed as part of the Education Amendments Act of 1972, prohibited discrimination on the basis of gender in educational institutions receiving federal aid, meaning that women's athletic programs had to be treated as equal to men's programs. In 1978 the AIAW championship was televised, and the same year a professional league called the Women's Basketball League (WBL) made its debut. Featuring eight teams, the league lasted three years. The AIAW disbanded in 1982, but that same year the NCAA held its first national championship for women. Three years later, in 1985, the Basketball Hall of Fame began inducting female coaches, players, and contributors. These inductees include important pioneers such as Ann Meyers, who was the first woman to receive a collegiate athletic scholarship; Carol Blazejowski; Cheryl Miller; Anne Donovan; and Nancy Lieberman-Cline.

In the 1990s interest in basketball at all levels continued to grow. The most important figure in this growth was guard Michael Jordan, who is considered by many to be the greatest player ever. Jordan's exceptional basketball skills and flair for entertainment helped keep basketball in the forefront of American culture as he led the Chicago Bulls to six NBA championships (1991-1993, 1996-1998) and led the league in scoring a record ten times. Other great players of the 1990s included Hakeem Olajuwon, Scottie Pippen, Charles Barkley, David Robinson, Karl Malone, John Stockton, and Shaquille O'Neal. Star players of the women’s professional leagues included Cynthia Cooper, Sheryl Swoopes, Teresa Edwards, Lisa Leslie, and Jennifer Azzi.

Beginning in the late 1980s, it became increasingly common for the best male collegiate players to leave college before graduating, as they chose to enter the NBA draft hoping to play professionally for large sums of money. The NBA, while affording young players this opportunity, has tried to curtail this practice. In 1995 the league enacted a limit on the amount of money a rookie could earn, called a rookie salary cap, hoping to discourage players from leaving school.

Following the 1997-98 season NBA owners and players could not agree on rules regarding a salary cap and several other issues, and the NBA owners instituted a player lockout. The dispute cancelled all league play until an agreement was reached in January 1999, resulting in a strike-shortened, 50-game season followed by a regular playoff schedule and championship series. Jordan announced his retirement from professional basketball after the labor dispute was resolved. The San Antonio Spurs, led by David Robinson and Tim Duncan, won the 1999 NBA title. The Los Angeles Lakers, featuring Shaquille O’Neal and Kobe Bryant, won the 2000 league championship. Duncan and Bryant are part of the next generation of superstars that the league hopes will carry on the legacy of past heroes such as Bird, Johnson, Barkley, and Jordan.