Holcomb and his crew of Justin Olsen, Steve Langton and Curt Tomasevicz had a four-run total of 3 minutes, 36.83 seconds a full half-second in front of silver medalist Maximilian Arndt. Defending world champion Manuel Machata of Germany took the bronze, trailing Holcomb by 0.80.
This was the second gold in four-man at worlds for Holcomb, following his victory at Lake Placid in 2009, and his triumph last week in two-man was a first for the United States at worlds since two-man began in 1931.
Holcomb, who turns 32 in April, also joined German greats Andre Lange and Christoph Langen as the most recent pilots to complete a sweep at worlds. Langen won the two-man and four-man in 2001 and Lange in 2003 and 2008.
"It's been interesting," said Holcomb, who's been driving for a decade. "This has always been my goal since I started this sport. It's something you shoot for, but realistically most people are never going to achieve it. You just go out there and give it your best, do what you can, and hope everything comes together at the right time. It has in the last few years. We've really started to click."
Three years ago Holcomb broke a 50-year gold-medal drought for America in four-man competition at world championships and took home the bronze in two-man. Two years ago, he won the first four-man Olympic gold for his country since 1948, and he has 15 individual World Cup medals.
Two-time Olympic champion Billy Fiske, former world champion Stan Benham, and Art Tyler all of them deceased are the names that first come to mind as the biggest stars of the sport in the United States.
Holcomb is poised to move to the top of that list, if he isn't there already.
"He's arguably the best U.S. bobsledder ever," said Darrin Steele, chief executive officer of the United States Bobsled and Skeleton Federation. "He will end the argument when he wins in Sochi. Then, there will be no doubt."
The U.S. finished with a nice haul at these worlds, an encouraging sign midway to the next Winter Olympics in Sochi, Russia: Holcomb's two golds, a gold in the team event, Katie Uhlaender's gold in women's skeleton, and a bronze won by Elana Meyers in women's bobsled.
"It's always what you shoot for," Holcomb said. "It's the first time we've won all three [bobsled] events. That's pretty incredible."
Rookie Nick Cunningham and his team of Jesse Beckom, Johnny Quinn and brakeman Dallas Robinson finished 13th in USA-3, nearly 3 seconds behind their teammates. John Napier was disqualified Saturday after push athlete Adam Clark slipped and fell out of USA-2 at the start.
On Saturday, Holcomb trailed Arndt by 0.15 seconds after a mistake-filled first run, but he made up the deficit with the help of his second straight 4.97-second start, the best starts of the day. That put USA-1 just 0.01 ahead heading to Sunday's final two heats.
It was below zero at dawn Sunday with the sun shining brightly over the Adirondack Mountains, perfect weather to decide the title.
Holcomb slid first and took his sled dubbed "Night Train" for a near-flawless ride after a push of 4.94 seconds, the best time of all four heats. The crowd at the start roared as Holcomb zoomed through a tricky turn near the bottom of the 20-curve layout. He finished in 53.92 seconds, giving a thumbs-up as he climbed from the sled after what would be the fastest run of the four-heat race.
That put the pressure on the Germans, and they were unable to match it.
Arndt, who won bronze last week in two-man, and his crew of Alexander Roediger, Kevin Kuske and Martin Putze slid second. They brushed a wall at the top, nearly flipping, and trailed by 0.05 as they were just getting started. The momentum that was lost at the top began to show on the clock, and the sled finished in 54.12 to fall 0.21 behind.
Machata fared even worse. Trailing Holcomb by 0.28 to start the day, he lost 0.11 at the top on a sloppy third run, was nearly a half-second behind midway down, and finished in 54.25 to fall 0.61 behind.
Even World Cup champion Alexsandr Zubkov of Russia was no match. He was fourth entering Sunday's heats, 0.43 behind, dropped a third of a second on the third run and finished 1.28 seconds behind in fifth, passed on the final run by Edwin Van Calker of the Netherlands.
"This is an intimidating track to start with, even for the Americans," Holcomb said. "There was a 20-degree (temperature) difference and that makes it harder, which makes it slippier, and then you get less control on a track that's already kind of out of control and crazy. Less control is even more intimidating. It's kind of where the home track advantage came in. I've been down this track a million times."
Between heats on Sunday, Holcomb did what he always does, letting the world know what was on his mind: "Solid first run. Need to relax, stay focused and do it one more time. Let's bring it home!" he tweeted.
He did just that with a 4.95-second push and a run of 53.99 seconds. USA-1 was the only sled to go under 54 seconds in the two days of competition.
"Not enough to win the gold medal," Arndt said. "He (Holcomb) did a good job today. His brakemen push him so hard at the top of the track. Good drives, so he's the best today."
Bobsled World Championships results
Sunday, At Lake Placid, N.Y.
Men Four-Man Final
1. United States 1 (Steven Holcomb, Justin Olsen, Steve Langton, and Curt Tomasevicz), 3:36.83 (54.34-54.58-53.92-53.99).
2. Germany 1 (Maximilian Arndt, Alexander Roediger, Kevin Kuske, and Martin Putze), 3:37.33 (54.19-54.74-54.12-54.28).
3. Germany 2, (Manuel Machata, Marko Huebenbecker, Andreas Bredau, and Christian Poser), 3:37.63 (54.38-54.82-54.25-54.18).
4. Netherlands 1 (Edwin van Calker, Arno Klaasen, Sybren Jansma, and Jeroen Piek), 3:37.94 (54.60-54.95-54.23-54.16).
5. Russia 1 (Alexsandr Zubkov, Philipp Egorov, Dmitry Trunenkov, and Maxim Mokrousov), 3:38.11 (54.38-54.97-54.27-54.49).
6. Latvia 1 (Edgars Maskalans, Daumants Dreiskens, Ugis Zalims, and Intars Dambis), 3:38.20 (54.69-54.93-54.21-54.37).
7. Canada 1 (Lyndon Rush, Jesse Lumsden, Cody Sorensen, and Neville Wright), 3:38.32. (54.88-54.75-54.21-54.48).
8. Switzerland 1 (Gregor Baumann, Patrick Bloechliger, Alex Baumann, and Juerg Egger), 3:39.09 (54.87-55.21-54.43-54.58).
9. Germany 3 (Francesco Friedrich, Ronny Listner, Michail Makarow, and Thomas Blaschek), 3:39.31 (54.84-55.08-54.42-54.97).
10. Great Britain 1 (John James Jackson, Stuart Benson, Bruce Tasker, and Joel Fearon), 3:39.45 (55.25-55.09-54.62-54.49).
13. United States 3 (Nick Cunningham, Jesse Beckom, Johnny Quinn and Dallas Robinson), 3:39.68 (55.21-55.35-54.53-54.59).
United States 2 (John Napier, Charles Berkeley, Adam Clark and Christopher Fogt), DQ.
Latvia 2 (Oskars Melbardis, Helvijs Lusis, Arvis Vilkaste, and Janis Strenga), DQ.