Lacrosse as we know it today is an adaptation of a very ancient stick & ball game played by the Indigenous inhabitants of North America. Stickball was very popular with the Indigenous communities primarily east of the Mississippi River, but it was also known to be played as far west as what was later to become California.
The older Indigenous game had several different forms and as many names for it as there were languages. Most often the stick comprised of a rounded, netted end in which to pass, catch, carry, and shoot a leather or wooden ball. Some games, like To'li in the southeastern US, were played with two smaller sticks. In the northern Great Lakes game, often referred to as Baggataway, a single stick with a rounded, netted end was used. The Iroquois game, known as Tewa'araton, used a stick that has a similar shape to today's modern sticks.(It is this version of stickball that was adapted by the early settlers as lacrosse.) In the Indigenous stickball games, a point was awarded for obtaining a goal often by hitting a post at either end of the field, throwing the ball through two goalposts, or crossing a goal line with the ball.
Since the game was widespread in Upper and Lower Canada, early settlers began to play the game as well and soon enough had athletic clubs from the various towns and cities playing against each other. In order to unify all the various rules, a lacrosse fanatic dentist from Montreal, Dr. William George Beers, created the first lacrosse rulebook and started the first National lacrosse association in 1867. Dr. Beers is known as the Father of Modern Lacrosse.
In Canada, lacrosse was a very popular spectator sport with thousands of people coming to watch important games. For the first 60 years, the only form of the game was played on a field, what we call 'field lacrosse,' and played primarily by men. As the modern game spread across the continent, and across the world, a women's game was started up in Scotland in 1890.
After World War 1, the popularity of lacrosse in Canada began to wane in favour of other sports. This led to experiments with a version of lacrosse being played indoors in the summer, when the ice was out of hockey rinks. By 1931 a professional league had started up and popularized the 6v6 indoor game we know as 'box lacrosse.' Eventually the indoor game became more popular than the field game. Box lacrosse has gone through a few changes over the past 90 or so years, but it essentially remains the same fast-paced, high-scoring game as it was back then.
Lacrosse in Oshawa was first noted as being played in an organized way in 1872, but there were likely many informal games played in local neighbourhoods prior to that. Oshawa has had many provincial and national championship teams over the years, even a world championship team! However, Oshawa is best known for the Oshawa Green Gaels, a Jim Bishop run Junior A team that won the National championship Minto Cup for a record 7 times in a row in the 1960's.
For more in-depth history of lacrosse, see the links in the sidebar.