Timeline of the National Football League

The American Professional Football Association is formed September 17, 1920, at Canton, Ohio, with Jim Thorpe elected president.[1] The fourteen teams were mainly drawn from the Ohio League, Chicago Circuit, New York Pro Football League and other teams from the lower midwest. A $100 membership fee was charged. The Chicago Tigers folded after the season.[2]

The American Professional Football Association is reorganized at Akron, Ohio on April 30, 1921, with Joe F. Carr elected as new league president.[1] With the low entry barrier of a $100 membership fee, the number of teams balloons to 21.[1] Four of these franchises would last only one season, with Tonawanda Kardex only making it through a single game. Three other franchises folded mid-season.

The APFA was renamed the National Football League on June 24, 1922.[3] Four new franchises were awarded.

A new and distinct Cleveland Indians franchise was formed. Two other teams joined the NFL, the Duluth Kelleys and the St. Louis All Stars. The St. Louis team folded after one season.

Before the season, the owner of the Cleveland Indians bought the Canton Bulldogs and "mothballed" it, taking the team's nickname and players to Cleveland for the season. The Canton Bulldogs had won the NFL championship in 1923, and won it again as the Cleveland Bulldogs in 1924.

The Canton Bulldogs were reactivated. Four other franchises were awarded, including most notably a New York City franchise awarded to Timothy J. Mara and Will Gibson for a $2,500 membership fee, the New York Giants.[1] This was the final season for the Rochester Jeffersons.

The league grew to 22 teams, a figure that would not be equaled in professional football until 1961, adding the Brooklyn Lions, the Hartford Blues, the Los Angeles Buccaneers, and the Louisville Colonels, with Racine Tornadoes re-entering. At a league meeting held February 7, 1926, each franchise's roster was limited to a maximum of 18 players, with a minimum of 15.[3]

Prior to the season, the league decided to eliminate the financially weaker teams. As a result, the league dropped from 22 to 12 teams, and a majority of the remaining teams were centered around the East Coast instead of the Midwest, where the NFL had started. The New York Yankees were added from the American Football League and the Cleveland Bulldogs returned.

The league drops to 10 teams, the Buffalo Bisons sat out the season and the Duluth Eskimos folded. The Cleveland Bulldogs moved and played as the Detroit Wolverines.

The league increased back to 12 teams with the addition of two franchises, the Staten Island Stapletons, and the Orange Tornadoes. Two mothballed teams activated for the season. Minneapolis re-entered as the Red Jackets along with the re-entry of the Buffalo Bisons.

Prior to the season, Brooklyn businessmen William B. Dwyer and John C. Depler bought the Dayton Triangles, moved it, and renamed it the Brooklyn Dodgers. The Orange Tornadoes relocated to Newark. The Portsmouth Spartans entered as a new team, bringing the total to 11 teams. The league roster limit was expanded to a maximum of 20 players, with a minimum of 16 required.[3]

The league decreased to 10 teams due to financial hardships caused by the Great Depression. While the Cleveland Indians joined as an expansion team, the league lost the Minneapolis Red Jackets and the Newark Tornadoes, and the Frankford Yellow Jackets folded midway through the season.

The Boston Braves enfranchised bringing the total to 8 teams.

The barrier to entry was raised again with the July 8 decision to increase the league membership fee to $10,000.[1] Despite the fee increase, three new teams were added to the league — the Cincinnati Reds, Philadelphia Eagles, and Pittsburgh Pirates. The league split into Eastern and Western Divisions with the winner of each division playing in the NFL Championship Game. The 1933 season would be the first in which no NFL team folds or suspends operations.

• Portsmouth Spartans moved to Detroit; renamed the Lions
• Cincinnati Reds cease operations during season, and are replaced by the St Louis Gunners for the final 3 games.

• Neither Cincinnati Reds nor St. Louis Gunners return for 1935 season. The NFL raised its roster limit to 24 players effective with the 1935 season and again to 25 players for 1936.[6]

The Cleveland Rams would join the league from the AFL II and the Boston Redskins would move to Washington, D.C. in 1937. The league raised the roster limit to 30 players per team effective with the 1938 season.[3]

The Pittsburgh franchise changed its nickname from the Pirates to the Steelers before the start of the 1940 campaign. The NFL also raised the maximum number of players allowed on a league roster from 30 to 33 players effective with the 1940 season.[3]

As America became more deeply embroiled in World War II, the Cleveland Rams suspend operations for the 1943 season due to a major loss in players. The Philadelphia Eagles and Pittsburgh Steelers were able to work around the player shortage by merging to form the "Phil-Pitt Steagles."

Size of the active roster reduced from 33 to 28 players per team.[6] Intent of this reduction was to appease the Office of Defense Transportation by reducing the impact of travel by road teams.[7] Additionally, teams primarily used day coaches rather than sleeper cars, a more efficient albeit less comfortable mode of travel.[7] This continued through the 1944 season.

• Boston Yanks enfranchised.
• Cleveland Rams resume operations.
• Steagles end merger, Eagles resume operations
• Steelers merge with Cardinals to form "Card-Pitt"

The Card-Pitt team was resplit into the Chicago Cardinals and Pittsburgh Steelers for the 1945 season. The Brooklyn Tigers franchise was merged with Boston Yanks, named simply "The Yanks." The Active player limit was returned to its pre-war size of 33 players.[6]

The National Football League began to colonize the Pacific coast when the Cleveland Rams moved to Los Angeles, California ahead of the 1946 season. With World War II at an end, the Boston Yanks resumed normal operations, although the Brooklyn Tigers franchise was permanently terminated. Effective with the 1948 season, the NFL again raised its roster limit for member teams, increasing the maximum from 33 to 35 players.[3]

The Boston Yanks ceased operations at the end of the 1948 season, with remains of the team enfranchised for 1949 as the New York Bulldogs. Size of the active roster was reduced to 32 players.[6]

• Eastern Division renamed to American Conference
• Western Division renamed to National Conference
• San Francisco 49ers, Cleveland Browns, and the first Baltimore Colts all enfranchised from now-defunct All-America Football Conference. The Colts fold after the 1950 season.
• New York Bulldogs change name to New York Yanks, move to National Conference
• Chicago Cardinals move to American Conference

The NFL increased the maximum size of team rosters from 32 to 33 players effective with the 1951 season. This would remain in effect through 1956.[6] The New York Yanks franchise terminated following the 1951 season.

The Dallas Texans franchise was launched with the remains of the now-defunct New York Yanks, but the team terminated after one season. It remains the last NFL team to fold due to financial reasons.

The 1953 season saw a renaming of the league's two conferences, with the American Conference renamed the Eastern Conference and the National Conference renamed the Western Conference. A second and distinct Baltimore Colts team was enfranchised from the remains of the Dallas Texans. Effective with the 1957 season, the NFL raised its roster limit from 33 to 35 players per team.[3] The roster limit was raised again for the 1959 season, this time to 36 players per team.[8]

In 1960 the American Football League (AFL) began operations with eight teams as a rival to the NFL. The Dallas Cowboys were enfranchised by NFL. The year also marked the move of the Chicago Cardinals to St. Louis.

The roster limit was raised to 38 players per team for the 1960 season.[8]

The NFL enfranchised the Minnesota Vikings in 1961, with the fledgling Dallas Cowboys moved to Eastern Division to balance division numbers.[9] The league also reduced the roster limit from 38 back to 36 players during these two years.[6]

The AFL's Los Angeles Chargers moved to San Diego.

In the AFL, facing a divided sports market due to the establishment of the NFL's Dallas Cowboys, the Dallas Texans moved to Kansas City to become the Kansas City Chiefs. The New York Titans were also renamed as the New York Jets.

In the NFL, the roster limit was raised in 1963 to 37 players and in 1964 to 40 players — a number which remained constant until the end of the 1973 season.[6]

The 1966 season saw the Atlanta Falcons enfranchised by the NFL and the Miami Dolphins by the AFL. The two leagues played the first AFL-NFL championship game (later known as the Super Bowl) after the conclusion of the season.

• NFL Eastern Conference divided into Capitol and Century Divisions
• NFL Western Conference divided into Coastal and Central Divisions
• New Orleans Saints enfranchised by NFL
• Atlanta Falcons move to Western Conference

• Cincinnati Bengals are enfranchised by AFL
• New York Giants move to Capitol Division
• New Orleans Saints move to Century Division

• New York Giants move back to Century Division
• New Orleans Saints move back to Capitol Division

• AFL and NFL merge
  • AFL Eastern and Western Divisions become AFC East and AFC West, respectively
  • AFC Central formed
  • NFL Capitol Division becomes nucleus of NFC East
  • NFL Central Division becomes NFC Central
  • NFL Coastal Division becomes nucleus of NFC West
  • NFL Century Division teams split up between AFC Central and NFC East
• Baltimore moves from NFL Coastal to AFC East
• Cincinnati moves from AFL West to AFC Central
• Houston moves from AFL East to AFC Central
• Cleveland moves from NFL Century to AFC Central
• Pittsburgh moves from NFL Century to AFC Central
• New York Giants move from NFL Century to NFC East
• St. Louis moves from NFL Century to NFC East
• New Orleans moves from NFL Capitol to NFC West

The Boston Patriots are renamed New England Patriots. Size of the active player roster was increased in 1974 from 40 to 47 players before being lowered to 43 the following season.[6]

• Seattle Seahawks are enfranchised
• Tampa Bay Buccaneers are enfranchised

There was realignment of divisions with Seattle moving from the NFC West to the AFC West and Tampa Bay moving from the AFC West to the NFC Central. In 1978 the size of the active roster was increased from 43 to 45 players, where it would remain through the 1981 season.[6]

The Oakland Raiders relocated to Los Angeles. After the first two games of the 1982 season the size of the active roster was increased from 45 to 49 players, where it would remain through the end of the 1984 season.[6]

The Baltimore Colts moved to Indianapolis in 1984. In 1985 size of the active roster was reduced again from 49 to 45 — where it would remain through the end of the 1990 season.[6]

The St. Louis Cardinals moved to Phoenix in 1988. In 1991 the league allowed teams to add a third "emergency" quarterback to their active 45 man rosters—a system that would remain in effect through the end of the 2010 season.[6]

• Phoenix Cardinals renamed Arizona Cardinals

• Carolina Panthers enfranchised
• Jacksonville Jaguars enfranchised
• Los Angeles Raiders move back to Oakland
• Los Angeles Rams move to St. Louis

• Cleveland Browns franchise deactivated
• Baltimore Ravens enfranchised with remains of deactivated Cleveland Browns

• Houston Oilers announce that they will move to Nashville and are renamed the Tennessee Oilers. They play the 1997 season in Memphis and the 1998 season at Vanderbilt Stadium in Nashville while a new stadium is built in Nashville.

• Cleveland Browns franchise reinstated
• Tennessee Oilers renamed Tennessee Titans

• The NFL realigns to create four divisions with four teams each in both conferences.
  • Arizona (NFC East) and Seattle (AFC West) join the NFC West
  • NFC Central renamed NFC North
  • AFC Central renamed AFC North
  • NFC South created
    • Tampa Bay moves from the old NFC Central
    • New Orleans, Atlanta, and Carolina move from the NFC West
  • AFC South created
    • Jacksonville and Tennessee move from the old AFC Central
    • Indianapolis moves from the AFC East
  • Houston Texans enfranchised

In 2011 the active roster limit was shifted from 45 + 1 emergency quarterback to an undifferentiated 46 players. This would remain in effect through the end of the 2019 campaign.[6]

• St. Louis Rams return to Los Angeles.[13][14]

• San Diego Chargers return to Los Angeles.[15][16][17]

• Oakland Raiders move to Las Vegas.[18][19][20]
• Washington Redskins adopt the temporary name of Washington Football Team in response to controversy over their previous name.[21]

The size of the active roster was increased to 47 players — 48 if there were 8 offensive linemen activated.[6]

The Washington Football Team was renamed Washington Commanders in 2022. In 2023 the 47 man active roster was expanded to allow a third "emergency" quarterback.[6]