US Soccer Federation chief Sunil Gulati, who announced the bid in New York with his Canadian and Mexican counterparts, insisted they had the full backing of President Donald Trump, despite the US leader's rocky relations with Mexico.
Gulati said 60 of the tournament's matches would be staged in the United States, with Canada and Mexico hosting 10 games each. The United States would host all knockout games from the quarter-finals onwards.
Gulati played down the possibility that politics could hamper the bid, emphasising that Trump was "especially pleased" with Mexico's involvement.
"The president of the US is fully supportive... We are not at all concerned at some of the concerns that some people may raise," Gulati said at a press conference.
Trump was elected last year after a campaign marked by rhetoric against Mexico, vowing to build a wall to keep out illegal immigrants he branded "criminals" and "rapists".
The joint bid will start as the heavy early favourite in the race, despite United States prosecutors leading the probe into football corruption which rocked the sport in 2015 and led to the downfall of former Fifa supremo Sepp Blatter.
Bid long time coming
A bid from the North America region for 2026 had long been regarded as inevitable by Fifa watchers.
That sense of certainty hardened last year, when Fifa's council ruled that neither Europe nor Asia would be eligible to run for the 2026 tournament on the grounds that the regions are hosting the next two World Cups. Russia is hosting the 2018 finals, followed by Qatar in 2022.
With Europe and Asia ineligible, the Confederation of North, Central America and Caribbean Association Football (CONCACAF) could in theory face potential competition from the Africa, South America and Oceania regional confederations.
The prospect of a fresh American bid gathered momentum in 2014 after the World Cup in Brazil.
That campaign captured the imagination of US sports fans, with huge crowds attending public screenings of games at cities across the country.
The country's club game is also booming, with record numbers attending Major League Soccer games in 2016.
The United States first hosted the World Cup in 1994, staging a commercially successful 24-team tournament that played out to packed stadia.
Canada, who have only made one World Cup appearance when they were eliminated in the first round of the 1986 finals, has never hosted the tournament.