Juneteenth marks the end of slavery in the country in 1865 with the end of the US civil war.
Though it was first officially made a holiday in 1979 by the state of Texas, last year on 17 June it officially became a federal holiday across the country.
Since Thursday around 19,000 flights have been cancelled amid the long holiday weekend travel rush, reported USA Today.
On Sunday, more than 4,200 flights were delayed and nearly 900 were canceled, as of 7pm ET, according to FlightAware, which tracks flights in real time.
Early on Monday morning, the website showed that 1,744 flights were currently delayed while 1,245 had been cancelled.
On Sunday the worst-affected airports included New York City’s LaGuardia, John F Kennedy International and Newark Liberty International airports, along with Hartsfield-Jackson Atlanta International Airport and Chicago O’Hare International Airport.
Saturday saw more than 850 flight cancellations.
The increased footfall this weekend saw Friday being recorded as the most popular air travel day of 2022, according to the Transportation Security Administration (TSA) data.
The last time airports were as crowded was during the Thanksgiving holiday in 2021. The TSA said that around 2,438,784 people were screened at airport security checkpoints nationwide on Friday, the highest checkpoint volume since 28 November, the Sunday after Thanksgiving.
Aviation industry members said that a shortage of skilled personnel including pilots is driving the cancellations amid increased footfall.
“We’re in a boom time for travel. We’re blowing away all records of all previous years. So you’ve got this surge in demand, and you’ve got limitations on staffing,” James Ferrara, co-founder and president of global host travel agency InteleTravel was quoted as saying to USA Today.