But the effort was plagued by squabbles. In 1967, two rival leagues were launched, the Fifa-backed United Soccer Association and the National Professional Soccer League.

Pele gave the NASL a lift in 1975, but rising salaries led to the league's demise

Although not enjoying the support of Fifa, the NPSL won a TV contract from the CBS network.

After a lacklustre year for both leagues, they merged to form the North American Soccer League.

But the merged league did not fare much better. Out of 17 teams during the first season in 1968, all but five folded.

Then, after five years of obscurity and semi-professional status, the New York Cosmos signed Brazilian superstar Pele for $4.5m.

Suddenly, the sleepy league was the talk of the football world and major players from around the world flocked to the US. The league expanded to 24 teams.

Attendance increased but not fast enough to keep pace with players' salaries, and by 1984, the league had folded.

The wild '90s

Lolly Keys joined the staff of the NASL's California Surf in 1978, but three years later the club ceased to exist.

"I thought that I had to get out of soccer. It has no future," she said.

But she has stayed with the sport, joining the American Youth Soccer Organisation, which helps organise youth football across the United States.

The 1994 World Cup in the US helped launch a new professional league

AYSO began in 1964 in California with 125 players. Now nearly 630,000 youth play in AYSO leagues across the US.

And the 1990s were especially not only for the AYSO but also for football in the US.

After the United States hosted the World Cup in 1994, AYSO saw a 15% increase in the number of youth in their leagues.

And the '94 World Cup helped jump-start a new professional league, Major League Soccer.

The Beckham connection

Lolly Keys remembers 1994 not only for the World Cup. It was also the year that Manchester United sent players to run a camp for AYSO.

The youth league met Sir Alex Ferguson and Martin Edwards the year before to talk about how Manchester United and AYSO could help each other.

AYSO sent some coaches to work with Manchester United, and the club sent a few players.

Sir Alex said that he could not send his top players, but "I'll send some lads," Ms Keys remembers him saying.

The team sent a David Beckham, the Neville brothers and Keith Gillespie.

The next year, Sir Alex helped the youth league out with training for coaches and referees.

"We just think they're wonderful. We're happy to hear them doing so well," she said.

A new national pastime?

And since then it has been onward and upward for AYSO and football in the US. In 1999, the US women's national team won their second World Cup title.

The US women's second World Cup victory in 1999 helped cap a great decade for football in the US

A women's professional league will begin play this year.

But will football ever displace baseball, basketball or American football in the hearts of Americans?

"In my future, I don't see that happening," Ms Keys said.

But football is a passion for life for many Americans, she said. They begin playing when they are young, and they keep playing as long as they can.

But it remains to be seen whether David Beckham become a household name in the US like Michael Jordan or Tiger Woods.

Whatever the outcome, Manchester United has probably chosen the best time in 25 years to break into the US sports scene.