1869___First game
      1875___First official game ball: an egg-shaped, leather-covered rugby ball 
       \______Field length reduced to 100 yards plus endzones
        \______15 players on each side
      1876___Crossbar added to field goal posts at 10 feet high
      1877___First uniform devised by Princeton player L.P. Smock
      1880___Scrimmage system established for putting ball in play
       \______11 players on each side
      1882___System of downs first used: offense had 3 downs to make 5 yards
       \______Player substitution first allowed
      1883___Points system adopted: FGs worth 5, TDs and conversions worth 4, safety 1
      1884___Points awarded for safety increased from 1 to 2
      1885___First official used
      1894___"Flying wedge" formation and similar formations outlawed
       \______Three officials used: referee, umpire, and linesman
      1895___Seven offensive players on the line of scrimmage first used
      1897___5 points awarded for a touchdown and 1 point for a successful conversion
      1903___First football only stadium built at Harvard
      1904___Field goal worth 4 points
      1906___Forward pass made legal
      1908___Field judge used in the officiating crew for the first time
      1909___Field goal worth 3 points
      1912___System of downs revised to 4 downs to make 10 yards
       \______Touchdown worth 6 points
      1915___Numbers added to jersey
      1922___Scrimmage line for conversion attempts established at the 5 yard line
      1927___Goal posts moved to the rear of the end zone
      1929___Scrimmage line for conversion attempts moved to 2 yard line
      1937___Numbers required on both sides of jersey
      1939___Helmets required
      1941___Players may substitute at any time but may not be withdrawn or the
             outgoing player returned until at least one play has intervened.
             "Platoon" football made possible
      1948___Unlimited substitution on change of team posession
      1951___Face mask added to helmet
      1953___Two-platoon abolished and players allowed to enter game only once in each quarter
      1955___Back judge used in the officiating crew for the first time
      1956___Rubber covered ball permitted
      1958___2 pt conversion adopted for a run or pass completion following a TD
       \______Scrimmage line for conversion attempts moved to the 3 yard line
      1959___Distance between goal posts increased to 23 feet, 4 inches
      1964___Platoon football returns.  Unlimited substitutions between periods and after a score
      1967___Numbering system according to position first used
      1972___Line judge added to officiating crew
      1973___Mouth protectors required
      1974___Substitutes must be in for one play and replaced players out for one play
      1983___Side judge added to officiating crew
      1988___2 pts awarded to defense for returning a conversion attempt by offense
       \______Kicking tee disallowed for field goal and conversion attempts
      1991___Distance between goal posts reduced to 18 feet, 6 inches
      1992___2 points awarded to defense for returning a fumble outside the endzone
      1993___Rubber covered ball outlawed
       \______Players who are bleeding or whose uniforms are saturated with blood must come out of 
              the game until their return has been approved by medical personnel
      1995___Overtime used for Division 1A for the first time
      1998___First "official" national champion for D1A: Fiesta Bowl winner Tennessee 
      2002___First woman to play in major college football: New Mexico kicker Katie Hnida