Tennis has come a long way since and the ATP's been part of the storied history.

The Grand Slam tournaments and all other national championships were open to amateur competitors only prior to 1968. Two years later tournaments around the world formed a unified circuit, which became the Grand Prix. In 1972, during the first week of the US Open at Forest Hills, the leading professionals joined forces to create the Association of Tennis Professionals.

This direction marked another defining moment in the history of the ATP, when a handful of the game's leading players met in a secluded stairwell at the US Open to discuss the need for a players' association. Under the leadership of newly elected Executive Director Jack Kramer and President Cliff Drysdale, the ATP came to life with a goal of changing the game for the better.

One of the initial acts of the organisation was the establishment of a computer ranking system that provided fair analysis of a player's performance as well as an objective means to determine entries into tournaments. The ATP Rankings began on 23 August 1973 and has continued through today as the official ranking system in men's professional tennis.

From 1974 to 1989, the men's circuit was administered by the Men's Tennis Council, made up of representatives of the International Tennis Federation (ITF), the ATP and tournament directors from around the world.

Although the period during which the MTC guided the game was one of tremendous progress and improvement, players began to feel more and more that they should have a greater voice in their sport. Players had realised the time had come for them to take more control over the game.

At the 1988 US Open, ATP CEO Hamilton Jordan (pictured), surrounded by many of the top players in the game, held the now-famous The ATP released "Tennis at the Crossroads," outlining the problems and opportunities facing men's tennis. One of the options available to the ATP was the formation of a new circuit, the ATP Tour.

Support for the new Tour was quick in coming as over 85 of the Top 100 players signed a letter of support for a new system. Later in the fall of 1988, 24 players, including eight of the Top 10, signed contracts to play the ATP Tour in 1990. Also that fall, tournament directors representing many of the world's leading events voiced their support for the players and joined them in what was to become a partnership unique in professional sports, with an equal voice in how the circuit is run.

The 2023 season marked the 34th year the ATP had administered the worldwide circuit of men's professional tennis.  In August, Jeddah, Saudi Arabia, was announced as the host city of the Next Gen ATP Finals, from 2023-2027.

Here is a look at some of the highlights through the years:

The ATP establishes the computer ranking system, providing a fair analysis of a player's performance and creating an objective way to determine entries into tournaments. The ATP Rankings are introduced on August 23 with Ilie Nastase debuting at No. 1. Other actions include placing tournament representatives on the road and standardising prize money distribution and the conduct and discipline code. The ATP shows its strength and sends message of player unity after players boycott Wimbledon to defend Niki Pilic's position against a Yugoslavian Federation suspension for missing a Davis Cup match. 
The Men's International Professional Tennis Council (MIPTC), made up of ATP, ILTF and tournament directors, is formed to govern the sport as an independent, democratic, international body for the administration of professional tennis.
The ATP Doubles computer rankings begin on March 1.
The Nations Cup, featuring eight competing nations, becomes the World Team Cup in Dusseldorf, the first ATP Championship.
Full-time MIPTC supervisors are employed on the men's tour, and Penn becomes the official ball of the ATP. In a ground-breaking move, four young Chinese players compete in U.S. tournaments for the first time in over 21 years after being sponsored by the ATP.
The ATP sets up a player pension fund.
ATP membership approaches 500.
At the request of the ATP, MIPTC passes a Drug Testing Rule, making tennis the first professional sport to institute a workable and well-designed drug-testing program.
In an effort to make the calendar more coherent, the MIPTC moves the Australian Open a month back to January ('87) and the Masters a month earlier to December ('86).
The players, under ATP CEO Hamilton Jordan, hold a press conference in the US Open parking lot to announce that they will assume more control of the game. "Tennis at the Crossroads" outlines a plan for players to form a new tour in which they would play a major role and bear greater responsibility for the future of the sport. The idea is quickly embraced by the membership. Eighty-five of the Top 100 ranked players sign a letter of support for a new tour within weeks of the news conference. Tournament directors representing many of the world's leading events voice their support for the players and join them in what was to become a partnership unique in professional sports; players and tournaments each with an equal voice in how the circuit is run.
All Top 50 players contractually agree to play the new ATP Tour in 1990. A new calendar is structured allowing for an eight-week off-season and tournaments are realigned.
Sponsored by IBM, the ATP Tour era begins with an equal partnership between players and tournaments. The circuit features 76 tournaments in 28 countries on seven continents, with prize money averaging a 50% increase at the events. Indianapolis tournament director Mark Miles is named ATP CEO.
The first television package for men's tennis broadcasts 19 tournaments to a worldwide audience.
The ATP Tour extends its global reach, adding Arabian Gulf tournaments in Doha and Dubai. Prize money continues to rise, increasing by 23%.
The ATP Tour launches its first ATP website, ATP Online, and further broadens its reach by enlisting pop star Seal to record the anthem "Bring it On" which he sings at the ATP Tour Awards Gala and Night of the Stars at the ATP World Championships in Hannover.
The Mercedes-Benz/ATP partnership begins with a four-year agreement. As the "Official Car of the ATP", Mercedes-Benz provides official transportation at ATP tournaments, showcases prominent car displays at tournament sites and positions its Mercedes-Benz "star" signage on nets.
The ATP Senior Tour of Champions is sanctioned.
Players form a new STARS program as the ATP Tour helps make players more accessible to media, sponsors and fans. ATP broadcasts extend their reach to more than 200 countries.
The ATP Tour changes its name to ATP for 2001, introduces a new logo and rebrands its nine premier tournaments the Tennis Masters Series.
A newly launched website, ATPtennis.com, highlights the new tournament structure. ATP Properties forms, instigating a more commercial focus and new marketing, licensing and broadcasting opportunities.
Players gain greater visibility with appearances in television shows and popular magazines, prompting the ATP to launch its own publication: DEUCE magazine. The ATP combines with the WTA Tour to create the "One Game" program, enacting initiatives to better serve professional tennis fans.
Etienne de Villiers is named ATP Chairman in June. ATP stars unite behind ATP World No. 1 Roger Federer to raise funds for tsunami victims, donating prize money and organising the "ATP All-Star Rally for Relief." At the exhibition, the ATP and UNICEF launch a global partnership called ACE, Assisting Children Everywhere.
De Villiers expands his role to become ATP Executive Chairman and President. The ATP signs several major new sponsorship agreements, including the naming of South African Airways as Official Airline. Stanford Financial Group becomes the Official Partner of ATP Doubles as doubles stars gain greater support and exposure through a promotional "ATP Doubles Revolution" campaign and new match format. The player challenge, utilising video review for close line calls, debuts in Miami and is successfully implemented at 13 tournaments.
The ATP introduces enhancements to fan, sponsor, media and player experience at tournaments, including elimination of best-of-5 set finals; reduced draw sizes at five ATP Masters Series events, making them 56-player fields to ensure player health and enhance TV scheduling; and Sunday starts to build Opening Weekends at ATP tournaments. The ATP also increases prize money for the first time since 2000 and creates a new multi-million dollar marketing fund. A renewed marketing effort encourages fans to rediscover the tandem game and find out why ATP "Doubles Rules." ATP revenues grow by 15%, a record 4 million fans attend ATP tournaments and broadcast hours grow with record numbers watching on television.
The top three players, Rafael Nadal, Roger Federer and Novak Djokovic, take a leadership role by becoming ATP Player Council members with Federer as president. It's the first time in the organisation's history the top three players have joined the council in the same two-year period. All worldwide tennis organisations (WTA, ITF, ATP & Grand Slam Committee) form an integrity unit. The ATP's "Feel It" player promotion campaign is implemented throughout the season. Sponsorship deals with South African Airways, Ricoh and Enel are renewed while a new agreement is struck with Barclays to become the sponsor of the Barclays ATP World Tour Finals in London.
The ATP World Tour is unveiled with a simplified tour structure that brings a rationalised, healthier player schedule, a $1 billion investment in infrastructure and facility upgrades and a 33% increase in player compensation. A new point scale for the South African Airways ATP Rankings is implemented and tournament tiers featuring ATP World Tour Masters 1000, ATP World Tour 500 and ATP World Tour 250 events.
During the season two major sponsors are announced with the signing of Corona Extra as a premier partner, and FedEx as a platinum partner. In November, ATP Executive Chairman and President Adam Helfant announces that the 2012 calendar has been approved to include the extension of the off-season to seven weeks. The increased break, designed to allow players more time for rest and training between seasons, is approved for the 2012-13 ATP World Tour calendars by the ATP Board at its London meetings.
The ATP unveils its new advertising campaign, 'GAME ON', featuring more than 50 players. A multi-year prize money agreement is announced, seeing levels on the ATP World Tour exceed $90 million (not including Grand Slams) for the first time by 2014. In two major sponsorship deals, Moët and Chandon becomes the ‘Official Champagne’ of the ATP World Tour and the State of Rio de Janeiro the official tourism destination. The ATP ACES For Charity grant programme is launched, with 12 $10,000 grants awarded to charitable causes nominated by tournaments and players.
Brad Drewett takes over as ATP Executive Chairman & President in January. Roger Federer captured his 17th Grand Slam title and by doing so, reclaimed the No. 1 ranking, passing Pete Sampras’ all-time record and ultimately setting a new mark with 302 weeks at the top. The Barclays ATP World Tour Finals welcomed a record 263,229 fans in London, with the four year total since the tournament moved to The O2 exceeding the 1 million mark. It was announced that the season-ending tournament would remain in London a further two years, through 2015, with Barclays extending its title sponsorship of the event. Both HEAD and Ricoh signed multi-year partnership extensions, whilst the ATP approved the move of an ATP World Tour 500 tournament to Rio de Janeiro in 2014. ATP formed a competition committee to evaluate and recommend changes at ATP World Tour and ATP Challenger Tour levels. In December, the ATP announced Emirates would become the new rankings sponsor.
The ATP announces new global partnerships with Emirates, Rolex and Tecnifibre. The ATP Heritage Programme is launched to celebrate the 40-year anniversary of the Emirates ATP Rankings and the history of the ATP, culminating with a No.1 celebration event at the Waldorf Astoria in New York. Brad Drewett, the then-current ATP Executive Chairman & President, passes away in May from Motor Neurone Disease. In the preceding 12 months, Drewett had led discussions resulting in significant prize money increases for all players across all Grand Slams. The ATP Board of Directors approves the re-categorisation of Queen’s and Halle as ATP World Tour 500 events from 2015, as well as a new ATP World Tour 250 event in Shenzhen, China, from 2014. The 2013 ATP World Tour season sets a new attendance record with 4.47 million fans on site. Chris Kermode is appointed as ATP Executive Chairman & President from 1 January 2014.
Chris Kermode takes over as ATP Executive Chairman and President on January 1, succeeding the late Brad Drewett. The ATP announces partnership renewals with FedEx and Enel, and a new global partnership with Vixlet. The season-ending Barclays ATP World Tour Finals sets a new attendance record of 263,560 - the biggest in its 45-year history. A Business Advisory Board, consisting of select global executives and a Legends Advisory Board of former high profile players, are both formed to assist with long-term planning.

The ATP agrees to new partnerships with Maui Jim, Peugeot, Infosys and Le Sports, as well as securing an enhanced partnership with Emirates that sees the award-winning airline become the Tour’s Premier Partner through 2020. The ATP launches its own social media network, MyATP powered by Vixlet. The Barclays ATP World Tour Finals are confirmed to stay in London a further three years, through 2018. The Tour achieves an all-time attendance record with 4.5 million fans attending on-site.


The ATP announces the launch of the Next Gen ATP Finals, set to take place in Milan from November 2017 featuring players aged 21-and-under.


The inaugural Next Gen ATP Finals takes place in Milan, with Hyeon Chung coming out on top in the new and innovative 21-and-under event. The ATP World Tour achieves an all-time attendance record with more than 4.5 million fan attending on-site, including 253,642 at the Nitto ATP Finals.


The ATP announces the launch of the ATP Cup, a new team event set to take place in Australia from January 2020 in partnership with Tennis Australia. A new 'ATP Tour' brand identity and 'Love It All' marketing campaign is unveiled for 2019.


The ATP achieves an all-time attendance record with more than 4.8 million fans attending on-site, while Emirates’ status as Premier Partner of the Tour is renewed for a further five years, from 2021-2025. An agreement is reached for Turin, Italy, to host the Nitto ATP Finals from 2021-2015.


The 24-country ATP Cup, staged in coordination with Tennis Australia in Brisbane, Perth and Sydney, launches the season, with Serbia clinching the inaugural title. Andrea Gaudenzi starts his four-year term as ATP Chairman and fellow Italian Massimo Calvelli begins serving as ATP Chief Executive Officer.