Sixty-four years later, about 100 credentialed U.S. media members are covering the tournament - and that doesn't even include staffers from the networks broadcasting the games.
Back home, millions of people are watching on giant screens or office computers, at bars and public gatherings. In their protected Brazilian bubble, U.S. players find out about it via email, text, tweet, Facebook, cable television and all sorts of other inventions that didn't exist in 1950.
"All the bars and the pubs and restaurants are packed, and it's all over social media and people are taking off work," goalkeeper Tim Howard said. "That says a lot. They do that for the Super Bowl. So the fact that they're doing it for the World Cup is special."
The Americans are getting ready in Salvador for Tuesday's second-round game against Belgium. The match comes on the heels of the anniversary of the famous 1-0 victory over England at Belo Horizonte, still considered by many the biggest upset in World Cup history.
Dent McSkimming of the St. Louis Post-Dispatch newspaper was the only American reporter there in 1950. Now every game is televised live back home, drawing audiences that would make every U.S. league other than the NFL jealous.
Stars in other sports are taking notice. San Francisco Giants pitcher Tim Lincecum pulled on a U.S. road jersey after throwing a no-hitter last week.
This kind of attention and hype would have been unimaginable not just in 1990, when the U.S. returned to the World Cup after a 40-year absence, but even as recently as 2010.
"Obviously when we were in Korea, when we were in Germany, South Africa, the support has always been there, but it's just a lot bigger," said defender DaMarcus Beasley, the first American to play in four World Cups. "We get a lot more mainstream people that never really watched soccer or been a fan of soccer. And obviously people are going to say, 'Ah, people only come out during the World Cup. They don't support every game.' But we see it differently. We see what's going on behind the scenes, and we know our support is growing in the right direction, and us getting out of our group is a way to help improve our growth from a soccer standpoint."
Players have cited the large crowds at home and the thousands of U.S. fans in Brazilian stadiums as forces that motivated them during difficult moments.
"It is the reason we exist," said Korey Donahoo, president of the American Outlaws supporters group, "to inspire a difference in the team and to help spur the players on to greater things."
The three U.S. group stage games averaged more than 18 million viewers between English-language ESPN and Spanish-language Univision. The 2-2 Sunday evening draw with Portugal was the most-watched soccer game in American history with 24.7 million TV viewers.
The finale against Germany started at noon EDT when much of the country was at work - or at least supposed to be. A record audience of 1.05 million streamed that match on WatchESPN.
"Four years ago it was impressive, and the fact that it seems even bigger now is a testament to our country," Howard said. "I don't know if we can get that type of electricity every weekend. I don't think that's where we're at as a country in terms of the soccer fanaticism."
By comparison, Boston's six-game World Series win over St. Louis last October averaged 14.9 million viewers on Fox, San Antonio's five-game victory over Miami in this month's NBA Finals averaged 15.5 million on ABC, and Los Angeles' five-game win over the New York Rangers in the NHL's Stanley Cup finals averaged 5 million on NBC and NBCSN.
But "American football" is still the king in the U.S. The opening weekend of the NFL playoffs this past season averaged 34.7 million viewers for four games.
"This is a very special time for us back home in America and with the growth of soccer," defender Omar Gonzalez said. "With us getting out of the group, it definitely helps a lot. The viewership on different channels has been great, and we want to keep it going."
A win over Belgium would advance the U.S. to a quarterfinal against Argentina or Switzerland on Saturday at noon EDT, another potential record-setter.
"We're on a positive trendline in this sport. I don't think there's any denying that," U.S. Soccer Federation President Sunil Gulati said. "What this does is, it jumps up to a much higher trendline."