Pre–1907

The first organized football club in Canada was the Hamilton Foot Ball Club, a predecessor of the Hamilton Tiger-Cats, in 1869. This was followed by the formation of the Montreal Foot Ball Club in 1872, the Toronto Argonaut Football Club in 1873 and the Ottawa Football Club (the future Ottawa Rough Riders) in 1876.^[1][2]

The first organized competitions were formed in 1883, when the Ontario Rugby Football Union (ORFU) and the Quebec Rugby Football Union (QRFU) were founded. At the time the sport was generally called rugby union or rugby football because its rules were similar to rugby union's, although this would change drastically in the coming decades. The following year, the two provincial unions would form the Canadian Rugby Football Union (CRFU), with Montreal winning the first national championship later that year. The CRFU collapsed before the decade was out, but was re-organized as the Canadian Rugby Union (CRU) in 1891, with Osgoode Hall winning the first CRU championship the following year.

The turn of the 20th century was marked by fundamental changes in the rules of the game. The ORFU was the first competition to adopt the Burnside Rules, which were to revolutionize the Canadian game. The QRFU and CRU initially resisted the changes, but by 1906 the Burnside Rules were in force throughout Ontario and Quebec. Although substantial changes (such as forward passing) were still to come, modern Canadian football would ultimately evolve from John Thrift Meldrum Burnside's code.

W. A. Hewitt was vice-president of the ORFU, and represented the Toronto Argonauts.^[3][4] He sought for ORFU to have uniform rules of play with the CRU, with a preference to use the snap-back system of play used in Ontario.^[5] In December 1906, The Gazette reported that a proposal originated from Ottawa for the ORFU and the QRFU to merge, which would allow for higher calibre of play and create rivalries.^[4] Hewitt helped organize the meeting which established the IRFU in 1907.^[6]

Interprovincial Rugby Football Union (1907–1959)

In 1907, the Hamilton Tigers and Toronto Argonauts of the ORFU joined with the QRFU's Montreal Foot Ball Club and Ottawa Rough Riders (Ottawa had been moving back and forth between the two unions over the past few years) to form an elite competition, the Interprovincial Rugby Football Union (also known as the "Big Four"). Montreal won the first championship that year, taking home the James Dixon Trophy. In 1909 Lord Grey, the governor general of Canada, donated a trophy to be awarded to the CRU champion. The trophy, which became known as the Grey Cup, was not won by an IRFU club until the Hamilton Tigers captured the trophy in 1913. Following the 1915 season, the competition was suspended because of World War I, and did not fully resume until 1920.

From 1925 until 1953, IRFU teams dominated Canadian football, winning 18 of the 26 Grey Cups its clubs contested in that timespan (the IRFU suspended operations from 1942 through 1944 because of World War II). During this period, the calibre of play in the IRFU was recognized as being on par with any league in North America. The Big Four attracted considerable interest in the United States and even had its games televised by the National Broadcasting Company for a time during the 1950s (in fact, these games were more widely available than their NFL counterparts). This interest eventually declined as the National Football League gained prominence and the American Football League rose in popularity. During this time, the IRFU became increasingly professionalized. However, in order to keep up the pretense of amateurism, players were usually paid under the table.

By the mid-1950s, the IRFU had dropped all pretense of amateurism, and it was clear that it was a far higher calibre competition than the ORFU (the Quebec union had faded from the scene in the early part of the century), the only purely amateur union still competing for the Grey Cup. Moreover, the Western Interprovincial Football Union had been gaining strength over the last two decades, and its level of play was almost on par with that of the IRFU. The WIFU's champion had faced the Big Four's champion in the Grey Cup final every season since 1945, and it proved capable of winning the Grey Cup on a regular basis during this decade. Following the 1954 season, the ORFU finally stopped challenging for the Grey Cup, thus making the game a contest between the champions of the IRFU in the East and the WIFU in the West. Although it was another four years before the amateurs were formally locked out of Grey Cup play, this marks the start of the modern era of Canadian football.

In 1956, the IRFU and WIFU agreed to form the Canadian Football Council. In 1958, the CFC withdrew from the CRU and renamed itself the Canadian Football League. The new league assumed control of the Grey Cup, though it had been the de facto professional championship for four years before then.

Eastern Football Conference (1960–1980)

The IRFU changed its name to the Eastern Football Conference in 1960. In 1961, the EFC agreed to a partial interlocking schedule with what was known by then as the Western Football Conference. Although the EFC was part of the CFL, its merger with the WFC was only a partial merger for the next two decades. During this time, the conferences maintained considerable autonomy, much like Major League Baseball's two leagues operated during the 20th century. For example, the East had a different playoff format until 1973 and a shorter schedule until 1974. During this time, attendances increased substantially for most clubs and television revenue gained prominence and importance. By the 1980s, however, rising player salaries had caused considerable financial losses for some teams. In an effort to bolster the league's stability, the CFL decided to proceed with a complete merger of the two regional conferences.

East Division (1981–1994, 1996–present)

In 1981, the CFL's two conferences agreed to a full merger and a full interlocking schedule. Although the EFC has carried on since that time as the CFL's East Division, full authority was now vested within the CFL. The decision to create a full interlocking schedule meant that the teams were playing fewer divisional games, consequently the league decided to add two extra divisional games per team, thus extending the schedule to 18 games per team starting in 1986.

The East Division has undergone major changes since the dissolution of the EFC. Following the 1981 season the Montreal Alouettes folded. They were refounded in time for the 1982 season as the Montreal Concordes. The new owners restored the Alouettes name in 1986, but this franchise folded shortly before the start of the 1987 regular season. Consequently, the Winnipeg Blue Bombers, the easternmost team in the West Division, were transferred to the East Division to keep the divisions equal in size. This led to the first "all-Western" Grey Cup in 1988 when the Blue Bombers won the East Division championship for the first time.

In 1994, the CFL decided to expand further into the United States after admitting the Sacramento Gold Miners as the first U.S. team a year earlier. This led to the addition of the two American-based teams in the East, the Shreveport Pirates and a team in Baltimore that would eventually be called the Stallions after the NFL successfully prevented the team from using the name "Colts". Baltimore would go on to win the East Division championship in 1994. For the 1995 season, all eight Canadian teams competed in the North Division, while the five American teams formed the South Division.

Prior to the 1996 season however, all of the American clubs disbanded. The owner of one, the Grey Cup champion Stallions, moved his organization to Montreal as the third and current incarnation of the Alouettes. However, while the Alouettes are now officially reckoned as having suspended operations from 1987 to 1995, they do not acknowledge their past as the Stallions. The pre-1987 divisional alignment was restored, only to see Winnipeg return to the East after one season when the Ottawa Rough Riders folded. The Blue Bombers returned to the West in 2002 after the Ottawa Renegades commenced play in the nation's capital. With the suspension of the Renegades in 2006, the Blue Bombers again were transferred to the East Division. With the East Division Ottawa Redblacks beginning play in 2014, the Blue Bombers moved back to the West Division again.

Grey Cup record

Prior to 1954, Eastern clubs dominated the Grey Cup games. Since 1954 however, the West has generally been on an equal footing and in recent decades has often dominated the East in the regular season. From 1954 to 2016, the East has won 27 Grey Cups and lost 35. This is not counting the 1995 season. Two of the East's Grey Cup wins were by the Blue Bombers, who have played in the West for most of their history.

IRFU champions

Champions of the Eastern Football Conference

Champions of the East Division