Summary

To get a sense for the growth in the variety of commonly practiced sports, I considered which organizations would have been tracking individual sports in an official capacity. The International Olympic Committee (IOC) has a fairly long modern history, but sports included in the Olympic Games are restricted by the organizations rules, so while the IOC list certainly includes many of the most popular sports, and reflects some shifts over the last century, it certainly does not include many emerging but popular sports, or sports that are very popular in a particular region (like American football). I wrote to a number of organizations that lobby on behalf of sports that may have international federations, but lack representation in the Olympics, but I was not able to obtain historic data from any of them. I also thought to consult lists maintained by the National Federation of State High School Associations (NFHS) and the National Collegiate Athletic Association (NCAA), but these share limitations similar to the sports represented by the IOC. At the other end of the spectrum, I found one website, Topend Sports, which has a fantastic list of sports from around the world which seems quite comprehensive, but unfortunately offers no date information (either documenting when the sport was created or when it became popular).

Findings

International Olympic Committee (IOC)

Some context on IOC terminology and rules:
The IOC uses the terms “event,” “discipline” and “sport” to organize their athletic competitions. An event is any competition that results in the awarding of medals, such as the women’s 100-meter backstroke. The discipline of swimming, which comprises various events like the backstroke, breaststroke and freestyle, is a branch of the sport aquatics.

For a sport or discipline to be considered for the Summer Olympics, it must demonstrate popularity among both genders in various parts of the world. Men from at least 75 countries and women from at least 50 countries should practice a given sport on four continents.

When determining which sports to include in an Olympic program, at least 25 of the sports offered must come from the 28 sports established by the IOC. Up to three additional sports may be added that are not from among this pre-established group.

src:
Greg Soltis. July 27, 2012. “The Incredible Evolution of the Olympics.” LiveScience.

After writing to the International Society of Olympic Historians, I was referred to Bill Malon, who maintains an extensive Excel document with data from 1896-2012, including:
Number of Events per Sport by Year (by gender)
Total # of Events by Year (broken down by gender)
Total # Sports by Year (broken down by gender)
List of Sports and Events by Year (by gender)
List and Total # of Countries by Year

Mr. Malon’s Excel file (originally shared as OGCompShort.xls) is available in this Google Sheets document:

A simple list of the number of sports in each Olympic Games by year is also maintained by Topend Sports: Olympic Games Sports Changes. The list notes which sports were added or dropped in each Games.

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Agencies That Support the IOC

SportAccord
An association composed of autonomous and independent international sports federations and other international organisations contributing to sport in various fields.

SportAccord promotes sports, increases its and its members’ recognition by the Olympic Movement, and organizes multi-sports games.

To be a Member, an organization must group together the majority of the National Federations throughout the world practicing its sport and regularly hold international competitions. To be an Associate Member, an organization can either group together the activities of several Members or National Olympic Committees for the purpose of organizing competitions, or have objectives recognized by the Council as benefiting the other Members of the Association.

(Previously known as GAISF, the General Association of International Sports Federations.)

src: SportAccord. “2014 Statutes.” Accessed April 7, 2016.

Members list – 106 members

Contact: sportaccord@sportaccord.com
EMAILED 4/13. No reply.

Also sent inquires to The Association of IOC Recognised International Sports Federations (ARISF), info@arisf.org, and the Alliance of Independent Recognised Members of Sport (AIMS), contact form. No reply from them either.

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Sports counted in the NFHS Annual Survey, 1969-2015

Counting each sport that gets its own major subject heading in the tables. For example, “Skiing — Alpine” and “Skiing — Cross Country” count for a total of two sports. However, “Football — 11-player”, which often includes three subheadings (“6-player,” “8-player,” and “9-player”), is only counted once. “Flag Football,” with its own heading is counted separately from “Football — 11-Player.”
For example:
[NFHS-skiing-headings.png]
…
NFHS-football-headings.png

Note: Each of the annual surveys are freely available, but this is a sampling of every five years.

1969/70 – 29 sports
1975/76 – 31 sports
   Added: Archery, Drill Teams, Table Tennis, Weightlifting
   Dropped: Rowing, Rugger
1980 – 36 sports
   
   Added: Canoeing, Crew, Eskimo Games, Judo, Soft Tennis, second Softball category
   Dropped: Rugby
1985 – 31 sports
   Dropped: Curling, Drill Teams, Eskimo Games, Soft Tennis, Table Tennis
   Added: Equestrian, Heptathalon
   Condensed to one entry each: Softball, Track & Field
1990 – 32 sports
   Added: Other
1995 – 38 sports
   Added: Adapted Sports, Competitive Spirit Squads, Team Tennis,
   De-condensed: Skiing, Softball, Track & Field
2000 – 35 sports
   Condensed: Skiing, Softball, Track & Field
2004/05 – 41 sports
   Added: 4 Dance categories, Flag Football, Skiing category, Snowboarding
   Dropped: Decathalon, Heptathalon, Pentathalon, Water Polo
   De-condensed: Skiing, Softball, Track & Field
2009/10 – 42 sports
   Added: Air Riflery, Rodeo, Synchronized Swimming, Water Polo
   Condensed: 3 Dance categories, 2 Skiing categories
2014/15 – 53 sports
   Added: Boce, Dance category, Decathalon, Heptathalon, Kayaking, Mixed Coed Valleyball,
   Mountain Biking, Rugby, Sailing, Soft Tennis, Surfing,

Srcs:
The National Federation Of State High School Associations.
“1969-2014 High School Athletics Participation Survey Results.” Pp. 1, 23, 56, 112, 176, 258, 344, 418, 501.
and
“2014-15 High School Athletics Participation Survey.” Pp. 1-2

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International Sports Federations

Wikipedia – List of international sports federations
Includes federations recognized by IOC, ASOIF, AIOWF, ARISF, IPC, and SportAccord. Many of the federations have Wikipedia pages showing the date of creation.

Topend Sports also maintains a list of international sport federations, sorted alphabetically by sport. Current total count: 171.
Note: No links to the federation websites. Links to internal pages about the sport – no date information, just short, general descriptions of the sports.

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More Comprehensive Sports Lists

Topend Sports maintains a “Complete List of Sports from Around the World.”

The list currently has 806 entries, but no date information. Separately, they maintain a list of “Ancient and Extinct Sports.”

Topend Sports also has an interesting list of “New and Unusual Sports” submitted by readers, but I think many of the sports are just theoretical.

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Other Resources

North American Association of Sports Economists

Journal of Sports Management
current editor: David Shilbury
Published by the North American Society For Sports Management (NASSM)
Indexed in Human Kinetic Journals

North American Society for Sport History (NASSH)

Sport In American History
group blog – primarily academic contributors
links page points to other orgs

The LA84 Foundation operates the largest sports research library in North America, the Paul Ziffren Sports Resource Center. It is a state-of-the-art research facility and learning center dedicated to the advancement of sports knowledge and scholarship. The Foundation also maintains a sizable collection of historic sport art and artifacts much of which was inherited from the former Helms Athletic Foundation Sports Halls of Fame. Its digital holdings, accessible to the public through its website, include not only a complete set of Olympic Official Reports, but also the full run of the Journal of Olympic History and its predecessor, Citius, Altius, Fortius through 2012.
[Description from ISOH]
NOTE: reference queries involving research charged $40/hour

Here’s an index to some older sports history journals available online. Seems like perhaps this should not be public, but there it is! And the full text of articles are available, but difficult to navigate (no search).