The best source of televised rugby in the United States is probably found on Fox Soccer Plus. Union and League are two different versions of rugby. The split came as a result of a dispute over player compensation between clubs in the Rugby Football Union late in the 19th century. As a result some of the northern clubs split off and formed their own Rugby "League". The whole issue is moot now, as both sports are fully professional. However the Union game is utterly dominant worldwide -- the only places you find League played as a serious sport is northern England and the Queensland and New South Wales states in Australia. In North America there are thousands of Union clubs -- League clubs do exist, but they are very far and few between. Over the last hundred years the two games have diverged in a number of ways, so much so that they hardly resemble each other, at least in the flow of play. The main differences are (1) that League has reduced the number of players to 13 from Union's 15 and (2) in the breakdown/tackle. Union uses a contested breakdown, which requires any player taken off their feet to release the ball which can then be picked up by any player (on either side) still on their feet. This means that the ball is up for grabs after every tackle. League uses a six "downs" system kind of similar to American football -- a League side has six uncontested downs or tackles to advance the ball and (hopefully) score. After the six down they have to turn the ball over to the other side. There are plenty of other differences, particularly in the scrums. If you want more information there is a wikipedia article which compares the two -- see