Flight crews called aviation police, who dragged him from his seat and down the aisle of the plane.
Additional video has come to light of the man bloodied after being removed from his seat.
Chicago police told NBC News that the man "became irate" after being chosen to give up his seat on overbooked flight and that police were called when he began raising his voice.
Police said the man fell after they tried to carry him off of the flight. He apparently hit his face on an armrest, NBC News reported.
He was taken to a hospital and treated for his injuries.
One of the officers involved in escorting the man from the flight has been reportedly placed on leave.
United Airlines gave WHAS this response to the incident:
“Flight 3411 from Chicago to Louisville was overbooked. After our team looked for volunteers, one customer refused to leave the aircraft voluntarily and law enforcement was asked to come to the gate. We apologize for the overbook situation.”
United Airlines has since posted a response on its Twitter page saying that they are reaching out to the passenger in question “address and resolve this situation.”
Passengers, before they boarded the flight Sunday, were offered $400 and a hotel room to willingly relinquish their seat to take a later flight scheduled for Monday, The Courier-Journal reported. When they boarded, they were told that four people would have to disembark and the offer was increased to $800. When no one volunteered, a computer randomly picked four passengers. A couple agreed to leave the flight, but the man in the video refused, , The Courier-Journal reported. There is no word who the fourth person was or if he or she left the flight.
Last month, teens who boarded a flight wearing leggings were removed by United Airlines. Three girls were traveling on an employee pass and the airline said that it has a no-leggings policy for employees when using the pass. Two of the girls left the flight. A third, who was also wearing leggings, put a dress on over the tight-fitting pants and was allowed on the flight.
The headline of this story has been changed to reflect that the flight was not overbooked, according to United spokesman Jonathan Guerin.