By Pravin Char

LONDON (Reuters) - Sam Querrey said this year's Wimbledon had been a triumph for the United States after the nation's best showing at the championships for 12 years.

The U.S. had six players in the singles fourth round, the country's highest number since 2004 and a far cry from 2014 when not a single American reached the last 16.

The women's challenge has been led by Serena and Venus Williams, who are through to the semi-finals. On the men's side, the best performers were Steve Johnson, who lost to Roger Federer in the fourth round, and Querrey who beat world number one Novak Djokovic on his way to the quarter-finals.

"It's been a great two weeks for the men's side especially," Querrey told reporters after losing 6-4 7-5 5-7 6-4 to Milos Raonic on Wednesday.

"The women pretty much always have at least Serena going deep, but all in all I thought it was great," he added.

"To have two guys in the third round, a guy in the fourth round, a guy in the quarters, we don't do that too often."

The U.S. have produced some of the game's greatest champions in years gone by, including Pete Sampras, Andre Agassi and John McEnroe.

But the last American to win the Wimbledon men's singles crown was Sampras in 2000, and no U.S. male has lifted a grand slam trophy since Andy Roddick landed the U.S. Open in 2003.

Querrey said he had gained a lot of confidence from his feats at Wimbledon this year.

"I feel like I've got a lot of momentum," he said. "I'm just going to try to keep going, put my foot down on the gas pedal."

(Editing by Ed Osmond)