For virtually the history of the sport, the States seems to have had a production line of talent, with new champions ready to take over when old ones fade.
But the increasing globalisation of the game means the strength in depth has never been greater.
Serena Williams has carried on sweeping all before her regardless, but there has been no papering over the rest of the cracks.
On the men's side, 2013 was a new low for the States - no American man reached the fourth round at any grand slam.
The retired Andy Roddick is still sorely missed and the next generation have not yet made an impression at the top of the game.
One player who has caught the eye is Stefan Kozlov, but he is 15 and what he needs more than anything is time and patience.
In the women's game, though, there is much for America to be excited about for 2014.
A generational shift appears not far away, and US players are at the head of it.
Twenty-year-old Sloane Stephens is the one who has made the most progress so far.
She built on her breakthrough year in 2012 and made at least the fourth round at every grand slam in 2013, including beating Williams to reach the semi-finals at the Australian Open.
Stephens ended the season ranked 12th and was an alternate at the WTA Championships in Istanbul featuring the top eight players in the world.
But Stephens is just one of 11 Americans ranked in the top 100, six of whom were born in the 1990s.
Thirteeen more players are ranked between 100 and 200 and the oldest of those is 24.
The best of the lot may well turn out to be 18-year-old Madison Keys, who is already in the top 40 and ended her season by reaching a first WTA Tour semi-final in Osaka.
Keys is the second-highest ranked teenager, only six places behind 19-year-old Eugenie Bouchard, who may not be American but is from the same continent - she hails from across the border in Canada.
Both women have overtaken Britain's Laura Robson, who had her breakthrough in 2012 and has found consistency tough to achieve this season.
Keys and Bouchard both have that test to come next season but it would be a surprise if they did not kick on.
Bouchard won 39 matches this season, more than twice as many as Robson, while Keys won 34.
Both women stand 5ft 10in tall and are archetypal modern players with big games and an aggressive approach.
Brad Gilbert, the former coach of Andre Agassi and Andy Murray, said of Keys in the New York Observer: "I think she can be top five and maybe even higher.
"I judge it on the eye test, which for me is her size, her athleticism and her weapons. Everybody knows her potential, but, if you're asking me, she has serious potential."
Bouchard pipped Keys to win the WTA's Newcomer of the Year award and has already been tipped by Martina Navratilova as a future grand slam champion.
In an interesting twist, Bouchard and Robson, who have been friends for a decade, will both be coached by American Nick Saviano.
Bouchard got in first and will travel with Saviano, while he will act more as a consultant for Robson, who will also work with Jesse Witten.
Whoever emerges on top in 2014, the real winner is likely to be the WTA, who will look to make the most of their young and highly marketable stars.
Overshadowed for a number of years by a great era in men's tennis, there are now real signs that it may be a different story in the women's game in the not-too-distant future.