Lacrosse has been played in Pennsylvania since the 19th century. Today, there are many respected amateur programs at the club, college and high school level, as well as several respected past and present professional teams in the National Lacrosse League (NLL) and Major League Lacrosse (MLL).
Intercollegiate lacrosse in the US, can trace its roots to 1877, when New York University beat Manhattan College, two to zero. Also in 1877, the Boston Lacrosse Club started up at Harvard, though a true varsity team at Harvard was not established until 1880. In 1879, the United States Amateur Lacrosse Association was formed by John R. Flannery, a well-known Canadian club player to coordinate the efforts of private, amateur lacrosse clubs in several Northeast cities, including one club that formed in Bradford, Pennsylvania. Flannery had grown up in Canada, been a member of the Montreal Shamrocks Lacrosse Club, and subsequently moved to the United States where he played for a number of amateur east coast clubs. In 1878 he organized a game billed as the National Championship between Union Lacrosse Club and Ravenswood Lacrosse Club of New York City. Encouraged by the turnout of some 40,000 spectators, Flannery set about organizing the disparate lacrosse clubs into a cohesive organization. Ravenswood Lacrosse Club with John Flannery went on to influence lacrosse at several other colleges, playing a well-publicized game against New York University in 1879.
In 1881, the first true varsity level intercollegiate lacrosse tournament was held, with Harvard defeating Princeton in the final, 3-0. This series led to the formation of a league in 1882, known as the Inter-Collegiate Lacrosse Association (the ICLA, later the ILA), which included New York University, Columbia, Princeton and Harvard. At the same time, Flannery's United States Amateur Lacrosse Association comprised eleven college and club teams, but by 1886 the number of clubs had risen to greater than 40. College organizations, including a varsity team at Lehigh University, soon were seeking admittance to the ILA. Lehigh fielded its first varsity squad in 1885, with the University of Pennsylvania, and Lafayette College at the club level, following suit in 1890. Lehigh and Swarthmore were accepted as members in the ILA in 1888 and 1891, respectively.